germination of some multipurpose tree species in five ... · insolação, da temperatura, substrato...
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Tropical Ecology 46(2):203–217, 2005 ISSN 0564–3295 © International Society for Tropical Ecology
Germination of some multipurpose tree species in five provenances in response to variation in light, temperature, substrate and water stress
NEERAJ KHERA1 & R.P. SINGH2
Department of Forestry, N.D. University of Agriculture and Technology, Kumarganj Faizabad
Abstract: Seeds of Acacia catechu, A. nilotica, Albizia lebbek, Dalbergia sissoo and Tectona grandis from five provenances of northern India were tested to evaluate the effect of light quality, temperature, substrate and water-stress on germination of seeds, and to assess the extent of intraspecific variation. Results indicated that germination of Acacia catechu, A. nilotica and D. sissoo was less dependent on light quality, whereas direct and far-red light enhanced germination in some provenances of T. grandis and Albizia lebbek, respectively. Seeds of all the five species exhibited variation regarding the range of optimum temperature required for maximum germination. Small-sized seeds showed higher germination in paper methods, whereas germination of medium-sized seeds was higher in sand and soil methods. T. grandis exhibited very poor results in paper methods. Some provenances of A. nilotica and Albizia lebbek were found to be tolerant to significantly high levels of water stress. Intraspecific variation in A. lebbek, for temperature requirement and stress tolerance, was conspicuous.
Resumen: Semillas de Acacia catechu, Acacia nilotica, Albizia lebbek, Dalbergia sissoo y Tectona grandis de cinco procedencias del norte de la India fueron probadas con el fin de evaluar el efecto de la calidad de la luz, la temperatura, el sustrato y el estrés hídrico sobre la geminación de las semillas, y para evaluar la magnitud de la variación interespecífica. Los resultados indicaron que la germinación de A. catechu, A. nilotica y D. sissoo fue menos dependiente de la calidad de la luz, mientras que la luz directa y el rojo lejano promovieron la germinación en algunas procedencias de T. grandis y A. lebbek, respectivamente. Las semillas de las cinco especies mostraron variación en términos del intervalo óptimo de temperatura requerido para obtener la máxima germinación. Las semillas de tamaño pequeño mostraron una germinación más alta en métodos que usan papel, mientras que la germinación de semillas de tamaño mediano fue mayor en métodos que usan arena y suelo. T. grandis mostró resultados muy pobres en los métodos que usan papel. Se encontró que algunas procedencias de A. nilotica y Albizia lebbek son tolerantes a niveles significativamente altos de estrés hídrico. Fue notable la variación intraespecífica en A. lebbek relacionada con los requirimientos térmicos y la tolerancia al estrés.
Resumo: Sementes de Acacia catechu, Acacia nilotica, Albizia lebbek, Dalbergia sisso e Tectona grandis de cinco proveniências do Norte da Índia foram testadas para avaliar o efeito da qualidade da insolação, da temperatura, substrato e stress hídrico na germinação, e avaliar a extensão da variação inter-específica. Os resultados indicam que a germinação da A. cachu, A. nilotica e D. sissoo era menos dependente da qualidade da insolação enquanto que a insolação directa e a vermelha longa aumentou a germinação em algumas proveniências da T. grandis e A. lebbek, respectivamente. As sementes de todas as cinco espécies apresentaram variação em relação ao intervalo da temperatura óptima necessária para a germinação máxima. As sementes de pequenas dimensões mostraram mais elevada germinação para os métodos no papel, enquanto a germinação das sementes de média dimensão foram mais elevadas para os métodos em areia e terra. A T. grandis exibiu resultados muito pobres nos métodos em papel. Algumas proveniências da A. nilotica e Albizia lebbek apresentaram-se tolerantes a elevados valores de stress hídrico. A variação intra-específica na A. lebbek, para as necessidades de temperatura e tolerância ao stress foi conspícua.
Key words: Germination, intraspecific-variation, light, provenance, substrate, temperature,
waterstress.
Introduction
Corresponding Author: e-mail; [email protected] Present Address: 1Department of Natural Resources, TERI School of Advanced Studies, Darbasi Seth Block, India
Habitat Center, Lodhi Road, New Delhi 110003. 2Department of Forestry, Kumaun University, Nainital
INTRASPECIFIC VARIATION IN PROVENANCES 204
Introduction
Acacia catechu Willd., Acacia nilotica Willd., Albizzia lebbek Benth., Dalbergia sissoo Roxb. and Tectona grandis Linn., are some of the most extensively distributed tree species throughout the northern plains of India. These species are of special importance in the arid-dry regions of northern India. These are the most sought after species when it comes to afforestation of wastelands, avenue plantation or agroforestry purposes. Being cost effective, the commonly adapted technique for regeneration of these species is direct seeding. As, seed characteristics of a species with wide distribution may vary from place to place, the seed germination of different provenances is of great importance for natural and artificial regeneration. Further, the intraspecific variation in response of seeds to light, temperature, substrate requirements and stress tolerance can affect the afforestation programs significantly.
The germination of seed is strongly influenced by variation in temperature, water stress and light requirements, and these factors often show significant interaction in their effects on germination (Bokhari et al. 1975; Erasmus & Staden 1986). Media (germination substrate) also play a significant role in germination because seeds have characteristic requirements as to the amount of moisture and oxygen needed for germination (Purohit et al. 1998.).
A large number of studies have been carried out on the effect of quality of light, temperature regime, substrate and water stress on germination of forest tree species including the species covered in the present study. However, in none of the studies, intraspecific variation in germination requirement and stress tolerance among provenances has been studied. The present study analyses the intraspecific variation in different provenances of these species when exposed to different environmental conditions.
Materials and methods
Seeds were collected from five provenances of Acaica catechu, A. nilotica, Albizia lebbek, D. sissoo and T. grandis in northern India. These provenances were: Bahraich (P1), Gorakhpur (P2), north Gonda (P3), south Gonda (P4) and Faizabad (P5). Details of the provenances are given in Table 1. For each species, twenty healthy and apparently disease free trees, at least 100 m apart were selected in each provenance, and pods/fruits were collected during the time of maximum seed availability. After collection, seeds
were cleaned, extracted and made homogenous to form five lots representing five provenances of that particular species.
Germination studies were conducted at the main Experiment Station, N. D. University of Agriculture & Technology, Kumarganj, Faizabad, in Northern India, which is situated at an elevation of 113 m above mean sea level at 260 47’
N lat and 820 12’ E long. The climate is tropical with an average annual rainfall of 1022 mm.
In all experiments, a factorial design with four 25-seed replicates was used. For germination, seeds were placed on cut sheets of germination paper in Petridishes and moistened with 5 ml of distilled water (ISTA 1985).
Light quality Red light was obtained by wrapping the Petri
dishes with red cellophane paper, while wrapping the Petri dishes with blue and red cellophane papers created far-red light conditions. Dark conditions were obtained by wrapping Petri dishes with two black carbon papers. Petri dishes covered with transparent cellophane sheets were used as control. 100 W incandescent bulb kept at a distance of approximately 1 m provided illumination (Rao 1986). These experiments were carried out in a dark room and low intensites of green light were used during handling. These tests were conducted at laboratory temperature.
Temperature The effect of temperature on the germination
of seeds was studied under following temperature regimes: 200C, 250C, 300C, 350C and 400C constant and 200/300C and 250/350C fluctuating tempera-tures, with 8 hours of higher range and 16 hours of lower range. The Petridishes were kept in the germination chamber with 8 hours of photoperiod. In case of fluctuating temperatures, photo-period was kept during the higher range of temperature.
Germination substrate Seeds were set for germination in six different
substrates. These substrates were: a) Top of the Paper (TP), where seeds were placed over the sheet of germination paper; b) Between Paper (BP), where seeds were placed between two sheets of germination paper; c) Top of Sand (TS), where sand was filled in enamel tray and seeds were placed over sand. After placing seeds, a thin layer of sand was placed covering the seeds completely; e) Top of Soil (TSI), same as TS method; and f) Soil (SI), same as sand method. Among these a and b were set in Petridishes and
KHERA AND SINGH
205
( )
Table. 1. Location of the provenances studied. Provenances Location Altitude Rainfall Temperatures (0C)
(m) (mm) Maximum Minimum P1 Bahraich 27030’N 81031’E 124 1177 37.5 9.8 P2 Gorakhpur 27054’N 82024’E 117 1044 34.8 10.1 P3 North Gonda 27024’N 82005’E 119 1330 37.0 10.5 P4 South Gonda 27024’N 82005’E 119 1245 37.0 10.5 P5 Faizabad 26046’N 82023’E 112 1142 39.0 8.4
c-f were set in enamel trays. In order to prevent the variation in the moisture level of substrata during the test period, all the enamel trays were covered with transparent sheets of cellophane paper and placed in the germination chambers along with the Petri dishes.
Seeds were set for germination in Petridishes as in the experiments of light and temperature. But the germination papers were moistened with different concentrations of mannitol solution to maintain water poetential of -5, -10, 15 and -20 bars (Uhvits 1946). Various levels of water stess were made according to the formula given by Helmerick & Pfeifer (1954). Solution of mannitol of respective concentration was added to the Petri-dishes whenever required during the experiment. Petri dishes where distilled water was used served as control.
In all the experiments, observation on seed germination were made after every three days up to 90 days in case of T. grandis and 60 days for the rest of the species. A seed was considered as germinated when the radicle had protruded about 2 mm beyond the seed coat. In the experiments involving sand and soil as substrate, emergence of radicle just at the surface was considered as germination. Germination value (GV) was calculated using Czabato (1962). Germination Energy (GE) was expressed as percent germination after 6 days in A. catechu, A. nilotica, A. lebbek and after 60 days in T. grandis (Ford-Robertson 1971). Measure of response breadth was calculated using Levin’s niche breadth metric (Levin 1968) as:
Water stress
sPsB
i 1
2∑=
i=1 where, Pi is the proportion of seed
germination response in state i, and S is the total number of states (treatments). The resulting measure B is a scale from 0 to 1 being the widest breadth.
Results and discussion
Light Results indicate that all the five provenances
of A. catechu exhibited a common trend in which the values of percent germination, GV and GE were highest under direct light condition (Table 2). However, germination was equally good under far-red light in P1, P2 and P3. Germination was significantly reduced in dark conditions in all provenances except P4. Provenance P5 differed from other provenances as germination was significantly reduced in red, far-red and dark conditions.
Out of five provenances of Acacia nilotica, three provenances exhibited similar trend, as there was no significant variation in germination under different light conditions. These three provenances are P1, P3 and P4. However, in P2 significantly higher germination was observed under far-red light and significantly reduced germination in dark. On the other hand, P5 exhibited significantly reduced germination in dark conditions.
Provenances of A. lebbek differed in their germination response to different light conditions. P1, P2 and P3 exhibited better germination in far-red light whereas, in P4 and P5, it was higher in red light. However, in all the five provenances, germination was greatly reduced in dark.
Seeds of D. sissoo from all the five provenances exhibited a significantly reduced germination under dark conditions. However, the provenances differed in the light quality in which they exhibited higher germination. In P1, P2 and P5, there was no significant variation in germination under direct, red and far-red light; in P3, germination was equally higher in direct and far-red light and it was greatly reduced in red light; in P4, germination was significantly different in all the light conditions. In T. grandis, germination was significantly higher under direct light as compared to other light conditions. (Fig.1).
Tab
le 2
. Ger
min
atio
n of
see
ds fr
om d
iffer
ent p
rove
nanc
es u
nder
diff
eren
t lig
ht c
ondi
tions
. Pr
oven
ance
Ligh
tAc
acia
cat
echu
Ac
acia
nilo
tica
Albi
zia
lebb
ekD
albe
rgia
sis
soo
Tect
ona
gran
dis
G
%
GV
G
E (%
) G
%
GV
G
E (%
) G
%
GV
GE
(%)
G%
G
V
GE
(%)
G%
G
V
GE
(%)
P1
Dir
ect
93
218.
2 93
91
19
.02
5466
11.5
37
9455
9.4
94
140.
014
9
206 INTRASPECIFIC VARIATION IN PROVENANCES
Red
85
163.
9 85
90
10
.26
53
81
16.9
4796
521.
296
90.
012
9Fa
r-re
d90
20
1.5
90
95
16.8
4 45
90
48.4
4796
714.
596
40.
001
3D
ark
87
19
7.3
78
90
18.2
9 50
49
6.07
3385
523.
485
70.
001
6
P2D
irec
t89
19
9.6
89
86
33.0
2 63
3214
.620
2816
.128
220.
391
19R
ed67
15
2.5
67
88
44.8
0 72
24
10
.019
2415
.324
120.
036
12Fa
r-re
d85
17
9.5
85
94
21.7
5 84
30
8.33
2022
12.3
2210
0.02
510
Dar
k
79
183.
4 79
69
11
.05
38
82.
678
189.
8210
90.
020
9
P3D
irec
t97
22
4.5
97
94
136.
24
8473
29.4
4463
85.2
6312
0.01
98
Red
82
167.
8 82
94
63
.15
85
42
5.90
2254
74.5
548
0.00
85
Far-
red
92
191.
5 92
92
66
.90
75
7629
.237
6180
.461
100.
012
8D
ark
89
20
1.7
89
91
120.
21
76
589.
5020
5056
.216
40.
002
4
P4D
irec
t95
23
1.6
95
94
69.2
3 77
435.
4226
7832
5.0
7818
0.26
010
Red
81
152.
1 75
91
60
.45
82
58
6.45
3265
266.
965
150.
189
9Fa
r-re
d89
18
4.3
89
91
89.9
6 78
46
4.20
2670
196.
470
110.
093
5D
ark
92
21
0.4
92
90
55.7
6 65
34
4.34
2154
98.3
054
100.
084
3
P5D
irec
t94
22
5.6
94
8218
.4
7340
3.84
2184
252.
584
60.
002
6R
ed66
14
3.6
58
73
11.6
5 48
51
7.
0030
8325
0.3
834
0.00
22
Far-
red
84
156.
2 85
80
33
.77
75
373.
9221
7923
3.6
793
0.00
11
Dar
k69
15
8.2
61
79
11.8
7 49
28
1.98
1576
231.
776
30.
001
2
CD
for
A 5.
2332
.93
5.23
5.94
8.9
9.07
5.78
3.2
6.83
6.52
55.3
46.
52
4.49
0.04
4.26
C
D fo
r B
5.
3833
.81
5.38
6.09
9.15
7.17
5.96
3.27
7.04
6.68
56.8
16.
68
4.62
0.04
4.39
C
D fo
r A
x B
8.
2451
.88.
249.
3114
.05
11.0
99.
095.
0410
.79
10.2
787
.11
10.2
77.
100.
066.
67 A
= P
rove
nanc
e, B
= L
ight
qua
lity;
GV
= g
erm
inat
ion
valu
e; G
= ge
rmin
atio
n
KHERA AND SINGH 207
Fig.1. Germination behavior of seeds under different light conditions (data averaged across provenances)
Response breath were wider for light condition in A. catechu, A. nilotica and D. sissoo, and comparatively narrow in A. lebbek and T. grandis, showing that the germination of the former three species is less dependent upon the type of light quality (Table 3).
Temperature All the five species exhibited a common trend
in which germination was significantly low at 200C (Fig.2). It increased from 200C to higher temperatures, reached a peak point and then declined at further high temperatures. This may be due to the fact that as the temperatures rise, changes in protein conformation occur which actually promote the germination process, but further conformational changes occur which are deleterious to it as temperatures become too high (Bewley & Black 1985).
Provenances differed in the peak point, i.e. the temperature for highest germination. In A. catechu, seeds from P1, P2, P3 and P5 exhibited highest germination in the constant temperature range of 30-350C and fluctuating temperature of 20/300C. However, temperature range for the seeds of P4 was 30-400C constant and fluctuating temperature of 20/300C. Germination of seeds of A. nilotica was not affected significantly by temperature of 20/300C. Germination of seeds of A. nilotica was not affected significantly by
temperature variation in the range of 25-400C, it was highest at 25/350C fluctuating temperature. Among the five provenances of Acacia nilotica, P4 emerged as the most tolerant one, as the rise or decline in germination over different temperatures was not significant. Tolerance to a wide range of temperature may help the species to germinate in adverse climatic conditions and extend its natural distribution range. Kozlowski (1970) and Osmond et al. (1980) also stated that species, which germinate readily over a relatively wide range of temperatures, should be easier to establish in the field than those with highly specific temperatures.
A temperature range of 30-350C was found to be favourable for seed germination of D. sissoo in all the provenances.
Different provenances of A. lebbek and T. grandis exhibited differential germination response to various temperature ranges (Table 4). In case of Albizia lebbek, germination was highest at 20/300C and 25/350C fluctuating temperatures in P1, whereas P2 exhibited highest germination at 25/350C. In P3 and P4, germination was higher at 30-350C constant temperature and 25/350C fluctuating temperatures. In P5, the germination was highest at 350C and 25/350C. It shows that P1 had a wider tolerance range for temperature. In T. grandis seeds of P2 were found to have wider tolerance range for temperature.
INTRASPECIFIC VARIATION IN PROVENANCES 208
It breathniloticrangetempefairly The dnilotictemperisingconne1973) rise inincreagermiand tempethose
Table 3. Levin’s B (response breadth) for different species for various parameters on differentenvironmental factors.
Species Provenance Environmental factors Light Temperature Substrate Water Stress A. catechu P1 1.00 0.98 1.00 0.98 P2 0.99 0.99 0.99 0.99 P3 1.00 0.99 0.99 0.99 P4 0.99 1.00 1.00 1.00 P5 0.98 0.99 0.99 0.99 Average 0.992 0.990 0.994 0.990 A. nilotica P1 1.00 1.00 0.99 0.99 P2 0.99 1.00 0.98 0.99 P3 1.00 1.00 0.98 1.00 P4 1.00 0.99 0.99 1.00 P5 1.00 1.00 0.99 0.99 Average 0.998 0.998 0.986 0.994 A. lebbek P1 0.96 1.00 0.99 0.90 P2 0.85 0.88 0.85 0.98 P3 0.96 0.83 0.96 0.98 P4 0.97 0.82 0.95 0.98 P5 0.96 0.83 0.94 0.96 Average 0.940 0.872 0.938 0.960 D. sissoo P1 1.00 1.00 0.81 0.95 P2 0.98 0.99 0.90 0.86 P3 0.99 0.99 0.93 0.98 P4 0.98 0.99 0.78 0.84 P5 1.00 0.99 0.92 0.81 Average 0.990 0.992 0.868 0.888 T. grandis P1 0.85 0.96 0.73 0.69 P2 0.87 0.87 0.78 0.60 P3 0.91 0.89 0.71 0.62 P4 0.95 0.89 0.72 0.63 P5 0.92 0.79 0.76 0.55 Average 0.900 0.880 0.740 0.618
is evident from the expression of response s that among the five species, seeds of A. a showed maximum tolerance to a wide of temperatures as, except very low ratures, germination of this species was good at all temperatures in all provenances. ecline in the germination percentage of A. a and T. grandis after a certain rature, when germination value was still , may be due to the fact that a causal ction may exist (Gulliver & Heydecker between the decline in percentage and the rate, as high temperatures are likely to
se the rate of many component processes of nation. In seeds in which they still function are well coordinated at the higher ratures the rate of germination increase, in which they are not will tend to fail.
Except D. Sissoo and A. catechu, all the species exhibited inverse relationship between temperature and occurrence of germination. Bernstein (1975) and Rana (1977) have emphasized the importance of early initiation and completion of germination process since they found that this phase is relatively more sensitive and often more decisive than subsequent growth stages.
Germination substrate Germination substrate was found to play a
significant role in the germination behaviour of seeds of all the five species (Fig.3). Seeds of A. catechu from all provenances, except P5, exhibited higher germination in BP, TP and TS methods. In P5 germination was not affected by the type of substrate (Table 5). Seed germination
KHERA AND SINGH
209
in P1 and P5 provenances of A. nilotica did not vary in different substrates. However, in P2 and P3, germination was significantly low in sand and soil methods. P4 exhibited slightly less germination in soil method.
Germination was quicker in paper method in all species excepting T. grandis, in which germination was quicker in soil method (Table 5). This may be due to the fact that seed of this species being large and round shaped were not properly moistened in paper methods. Proper moistening of teak seeds is perhaps an essential requirement to germination (Kehera, 2004 unpublished)
Seeds of A. lebbek from all provenances exhibited significantly high germination in BP and TS methods. P4 showed higher germination in BP and sand method. Seeds of D. sissoo exhibited higher germination in paper methods, however, P1 and P5 showed highest percent germination and GV in BP, whereas P2, P3 and P4 showed their highest values in TP method.
In case of T. grandis, the effect of substrate was more pronounced as compared to other species. Seeds from all the provenances exhibited higher germination in soil method, and
significantly reduced germination in paper methods.
Fig. 2. Germination behaviour of seeds under different temperature (data averaged across provenances).
Response breaths were wider for A. catechu and A. nilotica, showing their adaptability to various types of germination substrates; slightly narrow for A. lebbek and D. sissoo indicating that germination of these species is influenced by the type of germination substrate (Table 3). T. grandis exhibited a narrow (0.72) response breath depicting that germination of this species is largely dependent on the type of germination substrate. It was also observed in the study that, species with smaller seed size, viz., A. catechu and D. sissoo exhibited higher germination in paper methods as compared to sand and soil methods. Germination percentage, in both species, was fairly high in TS method also but germination value was remarkably less. This may be due to the mechanical obstruction posed by the sand particles on the emerging radicle, resulting in lower values of GV and GE. Also, seeds of D. sissoo have very delicate and thin seed coat, which is likely to get damaged by sand abrasion, resulting in poor germination percentage. Aldhous (1972) also found that sand
is not suitable for very small seeds. Higher germination in paper methods for small sized seeds have also been reported for Alnus neplaensis. On the other hand, A. nilotica and A. lebbek performed fairly good in both paper and TS methods. This may be due to the fact that these species have thick seed coat and large sized seeds, which require proper moisture conditions in order to get rid of seed-coat dormancy. Further as the germination periods is also longer in these species, sand and soil restrict the spread of fungi. Catalan (1992) also found that in Prosopis flexuosa and P. chilensis the use of either sand or paper gave similar results.
s not suitable for very small seeds. Higher germination in paper methods for small sized seeds have also been reported for Alnus neplaensis. On the other hand, A. nilotica and A. lebbek performed fairly good in both paper and TS methods. This may be due to the fact that these species have thick seed coat and large sized seeds, which require proper moisture conditions in order to get rid of seed-coat dormancy. Further as the germination periods is also longer in these species, sand and soil restrict the spread of fungi. Catalan (1992) also found that in Prosopis flexuosa and P. chilensis the use of either sand or paper gave similar results.
INTRASPECIFIC VARIATION IN PROVENANCES 210
T. grandis exhibited very poor germination when paper was used as substrate, while germination was high using soil and sand as substrates. This was in contrast to the findings of Purohit et al. (1998) who reported that large as well as medium or small sized seeds showed better germination in both Paper and TS method. The reason of poor germination of teak in paper method is that teak seeds are quite large sized, and moreover they need sufficient humidity to germinate (Khera 2003, unpublished), and it is not possible to cover the surface of teak seeds completely in paper methods.
T. grandis exhibited very poor germination when paper was used as substrate, while germination was high using soil and sand as substrates. This was in contrast to the findings of Purohit et al. (1998) who reported that large as well as medium or small sized seeds showed better germination in both Paper and TS method. The reason of poor germination of teak in paper method is that teak seeds are quite large sized, and moreover they need sufficient humidity to germinate (Khera 2003, unpublished), and it is not possible to cover the surface of teak seeds completely in paper methods.
Fig. 3. Germination behavour of seeds under different substrates (data averaged across provenances).
KHERA & SINGH 211
Tab
le 4
. Ger
min
atio
n of
see
ds fr
om d
iffer
ent p
rove
nanc
es in
diff
eren
t tem
pera
ture
s.
Prov
enan
ceTe
mpe
ratu
re
Acac
ia c
atec
hu
Acac
ia n
ilotic
aAl
bizi
a le
bbek
Dal
berg
ia s
isso
oTe
cton
a gr
andi
s
G%
G
V
GE
(%)
G%
G
V
GE
(%)
G%
G
V G
E (%
) G
%
GV
G
E (%
) G
%
GV
G
E
(%)
P1
20
0 C85
81.1
069
853.
2112
321.
910
8115
1514
0.02
1 6
250 C
85
214.
2 85
89
14.6
3 26
41
9.2
2180
1414
9
0.06
3 10
300 C
94
221.
0 94
90
29.4
6 57
60
19.5
37
9421
214
0.34
6 17
350 C
94
226.
1 94
90
100.
6 63
68
49.5
39
9324
247
0.89
4 24
400 C
87
172.
4 87
91
199.
6 84
67
64.6
50
8423
23
0.90
1 23
200 /3
00C
9619
1.4
9689
183.
469
7076
.349
9015
150.
321
1525
0 /350
C
9720
5.9
97
9620
4.3
9074
114.
160
8124
240.
462
24
P220
0 C78
92
.10
78
761.
76
122.
14
204.
906
90.
016
625
0 C77
17
9.9
77
7819
.3
28
199.
68
2211
.422
160.
084
1230
0 C88
19
6.4
88
8063
.0
73
2320
.321
2313
.123
300.
541
2835
0 C89
20
4.2
89
8158
.4
64
2935
.621
2312
.923
350.
726
3340
0 C81
19
4.3
81
7772
.9
41
1619
.512
189.
6018
430.
929
4020
0 /300
C83
199.
883
7861
.261
3031
.429
1910
.419
260.
304
2625
0 /350
C
6715
3.1
6782
81.3
7641
61.2
3415
8.30
1529
0.49
028
P320
0 C89
54.3
0 68
83
4.6
12
211.
95
5740
.115
50.
003
225
0 C89
20
9.4
89
8471
.2
32
346.
912
6075
.060
110.
015
930
0 C98
22
6.2
98
9110
1.2
81
7336
.248
6588
.465
180.
391
1635
0 C97
23
0.4
97
8798
.6
80
7659
.454
6487
.264
240.
529
2240
0 C84
19
1.6
84
8056
.5
78
2013
.518
5079
.650
210.
601
2020
0 /300
C98
216.
598
8810
6.9
7356
26.2
4355
83.6
5516
0.31
116
250 /3
50C
8810
0.5
8894
126.
385
7864
.468
4859
.948
200.
409
20
C
ontin
ued…
INTR
ASP
EC
IFIC
VA
RIA
TIO
N IN
PR
OV
EN
AN
CE
S 21
2
Tabl
e 4.
Con
tinue
d
P4
20
0 C79
93.4
0 51
88
6.1
388
1.0
372
214.
072
100.
031
10
250 C
85
221.
5 85
90
25.7
45
24
8.4
1280
361.
180
120.
094
1130
0 C96
23
6.1
96
9317
5.6
89
7217
.130
7935
1.1
7926
0.51
319
350 C
98
249.
4 98
95
268.
4 89
75
68.9
6175
312.
475
320.
634
3240
0 C97
22
0.1
97
9643
7.3
96
4959
.940
6528
6.1
6530
0.69
930
200 /3
00C
9825
3.6
9894
306.
481
6143
.250
7630
2.1
7621
0.43
620
250 /3
50C
8920
1.4
89
9739
8.6
89
7464
.468
5922
5.6
5927
0.53
122
P520
0 C75
52.1
0 43
79
2.0
5 12
1.3
571
95.9
425
0.00
32
250 C
8422
0.2
84
8119
.4
13
312.
112
7819
8.3
784
0.00
32
300 C
9422
4.2
94
8089
.6
62
433.
625
8425
4.6
8414
0.39
014
350 C
9523
0.6
95
8698
.5
67
6424
.630
8325
0.4
8324
0.45
924
400 C
7618
0.4
76
8810
4.2
72
3514
.922
7018
6.2
7020
0.53
220
200 /3
00C
9423
6.1
9485
97.9
6530
14.2
1580
223.
180
130.
319
1325
0 /350
C
8120
3.4
8191
121.
485
6931
.433
6514
2.4
6520
0.40
120
C
D fo
r A
3.71
21.1
3.98
3.
1212
.64.
645.
085.
664.
535.
736
.83
5.66
4.22
0.08
3.91
C
D fo
r B
3.
8525
.01
4.16
3.27
13.1
44.
855.
296.
084.
755.
9528
.39
5.88
4.41
0.07
4.09
C
D fo
r A
x B
7.
3347
.68
7.95
6.22
25.0
59.
2410
.09
11.2
39.
0311
.35
73.1
411
.23
8.39
0.18
7.70
Tab
le 5
. Ger
min
atio
n of
see
ds o
f diff
eren
t pro
vena
nces
, on
diffe
rent
type
s of
ger
min
atio
n su
bstr
ate.
Prov
enan
ce
Tem
pera
ture
Ac
acia
cat
echu
Ac
acia
nilo
tica
Albi
zia
lebb
ekD
albe
rgia
sis
soo
Tect
ona
gran
dis
G
%
GE
(%)
GV
G
%
GV
GE
(%)
GV
G
%
GE
(%)
G%
G
V
GE
(%)
G%
G
V
GE
(%
) P1
B
P93
21
8.2
93
9029
.2
53
5919
.736
9458
2.8
945
0.00
2 5
TP92
18
8.5
92
90
18.9
49
67
10
.139
6620
1.3
662
0.00
12
TS92
15
9.1
92
96
40.1
43
73
19
.238
7591
.43
6314
0.01
38
S87
14
6.3
72
82
27.3
25
74
30
.552
181.
016
210.
342
17TS
I91
14
4.9
91
94
19.8
27
56
22.4
2876
80.4
2417
0.25
612
SI86
13
9.8
68
90
20.7
9 62
13
.828
230.
30
280.
521
28
Con
tinue
d…
212 INTRASPECIFIC VARIATION IN PROVENANCES
KH
ER
A A
ND
SIN
GH
213
199.
6 83
81
.6
22
21
20
7
Tabl
e 5.
Con
tinue
d
P2B
P91
91
72
22
19.6
10.1
0.
002
7
18
6.2
85
31.3
13
.9
22
31
31
4
3
146.
4 78
39
.0
15.4
30
31
24
21
19
14
1.1
64
15.6
13
13
30
28
137.
6 82
17
.9
10.6
28
26
0
26
25
13
2.0
57
13
3.0
0 31
30
22
4.5
95
88.9
46
62
60
4
4
220.
5 94
14
9.6
30.2
47
74
74
1
1
19
3.6
92
52.6
25
.2
54
70
0 12
8
18
7.7
73
24.4
13
.7
36
43
32
18
16
18
9.4
86
37.3
10
.1
27
47
0 19
18
177.
9 68
10
.4
21
30
2 0
25
25
23
1.6
96
160.
0 31
80
80
3
3
22
2.4
94
67.9
82
82
2
1
20
5.2
88
135.
3 49
77
54
18
10
217.
0 94
10
1.8
17.5
38
31
19
25
19
201.
3 80
24
.9
63
4.9
0 24
16
197.
3 80
43
.6
45
2 3.
0 0
29
29
22
5.6
67
31.9
21
85
81
3
3
20
2.4
72
42
80
76
3
2
208.
1 71
49
80
65
6
6
197.
9 68
28
32
29
14
14
194.
5 74
25
58
29
.9
0 11
11
179.
7 72
24
0.
9 8
51
34.8
0
15
15
13
.17
7.80
10
.97
1.59
TP90
90
73
30
39
.60.
001
TS88
88
63
46
19
13
.50.
361
S87
69
44
3.
0 14
3.
3 0.
530
TSI
84
84
55
34
9.0
0.45
6
SI
81
52
5.
4 9
12
0.80
6
0.80
9
P3B
P97
97
86
72
35.0
84.8
0.
003
TP97
97
86
74
28
3.8
0.00
1TS
95
95
72
76
39.2
0.
019
S90
79
42
48
25
.5
0.38
4TS
I93
93
78
47
12
.4
0.40
5
SI
87
68
36
50
5.
9
0.53
9
P4B
P95
95
93
72
16
.9
40
324.
60.
002
TP95
95
91
5.
9 26
35
0.9
0.00
1TS
94
94
83
9.1
20
85.7
0.
253
S91
80
78
58
41
28
.6
0.50
1TS
I93
93
56
4.
6 20
0.
483
SI87
78
49
6.
5 26
0.
541
P5B
P94
94
38
41
3.1
254.
9 0.
002
TP94
94
16
.8
42
4.3
24
219.
30.
001
TS94
94
13
.2
26
7.0
23
86.2
0.
002
S92
78
12
.9
24
3.1
16
27.2
0.
393
TSI
91
91
15.0
28
1.
56
0.40
1
SI
89
65
15
.1
34
0.42
4
C
D fo
r A
3.39
26.9
55.
089.
267.
154.
264.
732.
925.
980.
651.
494.
61
4.06
0.
084.
10
CD
for
B
3.44
27.3
94.
929.
387.
254.
314.
822.
976.
050.
711.
634.
63
4.13
0.
074.
17
CD
for
A x
B
6.25
49
.56
9.36
17
.01
16.4
7 5.
37
3.65
7.
95
7.48
0.
15
7.57
KHERA & SINGH 213
Intraspecific variation was observed in A. nilotica, A. lebbek and D. sissoo, as seeds from different provenances differed in their germination response to different types of germination substrate.
Water stress In A. catechu, germination declined with the
increased water stress, however, all the five provenances differed in their germination response to different levels of water stress, P1 emerged as the most tolerant with a threshold
between -10 to -15 bars, whereas for all other provenances the threshold was between -5 to -10 bars (Table 6).
Fig. 4. Germination behavior of seeds in different substrates (data averaged across provenances)
214 INTRASPECIFIC VARIATION IN PROVENANCES
Some provenances of A. nilotica and A. lebbek exhibited an increased germination at moderately higher levels of water stress. In A. nilotica, though GV declined with increase in stress, percent germination of P1 and P3 increased significantly with an increased stress up to -5 bars. In all other provenances, there was no significant decline in percent germination up to -5 bars. Even at higher levels of stress, all
ce
Wa
Tab
le 6
. Effe
ct o
f diff
eren
t lev
els
of w
ater
str
ess
on g
erm
inat
ion
beha
vior
of s
eeds
. Pr
oven
ante
r st
ress
(bar
) Ac
acia
cat
echu
Ac
acia
nilo
tica
Albi
zia
lebb
ek
Dal
berg
ia s
isso
o Te
cton
a gr
andi
s
G
%
GV
G
E (%
) G
%
GV
G
E (%
) G
%
GV
G
E
(%)
G%
G
V
GE
(%
) G
%
GV
G
E
(%)
P1
0 22
1.0
90
29.0
1 58
59
93
93
22
17
94
94
20.6
37
579.
4 0.
351
197.
4 23
.66
49.2
73
89
89
20
13
19
4.5
24.7
2 38
.9
68
64
52
14
150.
2 15
.09
17.6
53
60
19
6
4 97
.8
11.7
1 16
53
89
.5
8 0
P2
0 19
6.4
80
63.9
6 72
23
20
.3
33
21
11.2
16
30
28
159.
9 23
.40
25.1
18
20
10
.2
15
19
17
14
3.6
18.9
4 16
.3
17
15
9.5
7 11
11
142.
1 18
.19
11
6.2
6 5
5 94
.6
14.6
8 3
5 3.
2 2
0 0
0
P3
0 22
6.2
80
47
62
55
18
15
20
5.6
26.2
9 31
.3
59
70
62
15
19
4.2
28.2
9 30
.45
69
68
60
8
6
16
4.6
33.3
3 20
.5
61
57
80.6
40
3
2 98
.3
22.2
1 43
44
35
.9
31
0
P4
0 23
6.1
90
30
79
79
26
19
214.
5 95
.7
13.8
36
37
86
.2
12
20
16
197.
4 94
.8
10.0
34
32
76
.6
11
11
6
18
4.3
29.1
9 32
69
.0
12
5 2
103.
2 27
.10
23
31
17.2
9
0
P5
0 22
4.2
75
14.3
2 48
42
83
83
14
14
20
2.2
10.0
6 54
43
43
9
7
19
1.6
5.97
76
46
13
3
1
16
4.2
67
6.67
56
26
44
.4
10
2 1
92.1
65
4.
59
18
23
43.8
7
0 0
0
10.1
9 4.
61
10
.19
4.63
17.4
2 7.
95
-590
90
93
55
98
53
6.2
0.19
8 -1
085
72
89
53
83
32
1.1
0.00
3 9
-15
73
65
89
18
61
111.
2 0.
001
-2
0 60
41
90
1
35
8.6
0 0
88
88
0.53
0-5
76
76
78
54
24
0.32
1-1
071
61
74
46
23
16
0.
101
-15
69
51
74
15
8.8
10
0.01
2
-20
58
24
71
0 17
3.
6
98
98
91
101.
07
7336
.383
.2
0.39
6-5
94
94
91
45
94
100.
2 15
0.20
5 -1
083
83
91
47
98
81
.2
0.11
2-1
580
76
90
25
86
0.
001
-2
0 71
59
91
0
62
9.0
0 0
96
96
93
175.
67
7417
.432
4.5
0.52
1-5
92
92
99
87
87
0.31
4 -1
085
76
95
78
78
12
0.
064
-15
81
70
98
12
9.2
28
0.00
6
-20
72
65
96
0 0
6.26
0
0
94
94
3.4
19
250.
8 0.
399
-589
89
76
28
3.
6 19
19
5.0
0.09
8 -1
083
78
64
9
9.1
30
137.
3 0.
001
-15
78
94
9 4.
2 22
0.
001
-2
0 69
43
1
53
3.6
C
D fo
r A
4.50
43.4
15.
104.
494.
56
3.01
6.09
4.49
10.1
95.
514.
610.
084.
61
CD
for
B
4.50
43.4
15.
104.
494.
57
3.01
6.12
4.49
10.1
95.
514.
630.
084.
63
CD
for
A x
B
7.65
97
.03
11.0
7.
65
7.86
5.
14
10.4
37.
65
17.4
2 9.
45
7.95
0.
015
7.95
KHERA AND SINGH 215
216 INTRASPECIFIC VARIATION IN PROVENANCES
provenances were considerably tolerant as is evident from their germination behaviour. No significant decline was observed in germination even up to -20 bars in P1, P3 and P4. However, in P5 the threshold was between -5 and 10 bars, and in P2, germination reduced significantly even at -5 bars.
In A. lebbek, germination percent and GV increased at a stress of -5 bars in all provenances except P4. The increase was maintained up to -10 bars in P5 and P3. P4 was the least tolerant provenance as, germination declined sharply even at a slight stress level of -5 bars. Seeds of D. sissoo and T. grandis were extremely sensitive to even a slight increase in stress level, except P3 where a stress of -5 bars enhanced percent germination and GV of D. sissoo seeds significantly.
Commencement of germination was delayed at higher levels of water stress in all the species except P3, P4 and P5 provenances of A. lebbek, and P4 and P5 provenaces of D. sissoo.
Wider response breadth of A. catechu, A. nilotica and A. lebbek shows their tolerance to increased stress levels. P1 and P3 provenances of D. sissoo also exhibited wider response breadth for stress tolerance (Table 3).
Across provenances, seeds of A. catechu, D. sissoo and T. grandis were highly sensitive to even a slight increase in the level of water stress as both germination percentage and germination value declined as the stress increased (Fig. 4). In A. nilotica and A. lebbek, however, germination percentage increased at moderately high levels of stress and afterwards in declined. This decline was significant only after –15 bars.
The decline in percentage germination in A. catechu, D. sissoo and T. grandis with increased levels of stress in the present study was consistent with the findings of Bokhari et al. (1975), Falleri (1994), Kaufmann & Eckard (1977) and Barnett (1969).
Reduction in seed germination at higher levels of water stress may be attributed to the moisture deficit in the seeds below the threshold which may lead to degradation and inactivation of essential hydrolytical and other groups of enzymes as suggested by Wilson (1971).
Among the species, A. nilotica and A. lebbek were found to be the tolerant to quite high levels of water stress. Bewley & Black (1985) also found in their experiments that the range of response to water stress was wide among species, from the very sensitive to the resistant. Resistant seeds may have an ecological advantage in that they can establish plants in areas in which drought-sensitive seeds cannot do so. Germination of these
two species, in the present study, was even benefited by slightly high levels of water stress.
It was observed that species with small sized seeds, viz. A. catechu and D. sissoo exhibited higher sensitivity and least tolerance to increased water stress than species with larger seeds, viz. A. nilotica and A. lebbek. This was in conformity with Rao & Singh (1989) who found that the inhibitory effect of water stress was markedly higher on the germination of smaller seeds than on larger seeds. However, in the present study T. grandis also exhibited lesser tolerance to the inhibitory effect of the water stress despite its bigger size.
Seeds of D. sissoo, A. nilotica and Albizia lebbek from different provenances responded diff-errntly to the inhibitory effect of water stress. Falusi et al. (1983) have also stated that intraspecific variations of drought tolerance can be quite marked, at least in species with a long distri-bution. Saint–Clair (1986) and Calamassi et al. (1980) have also demonstrated the existence of an early geographic variability between provenances and selection of those best adapted to water deficits.
Conclusions The differential germination response of
different provenances of the species to different environmental conditions suggests that a careful selection of provenances, for germplasm collection, is required in afforestation programmes. Variation among provenances was conspicuous in A. lebbek. Among the four environmental factors studied, intraspecific variation was more pronounced for water stress. Different provenances of all the five species varied in their response to increased level of stress. While some provenances were very sensitive to even a slight increase in the level of water stress, other emerged as almost resistant to high levels of water stress. Seeds from these provenances may be used for restoration of dry and degraded lands.
Acknowledgements
Authors are thankful to Dr. B.P. Singh, Head of the Department, for providing necessary facilities, and Dr. A. K. Saxena for his valuable suggestions. The first author is thankful to the Indian Council of Forestry Research & Education, Dehradun, for financial support.
KHERA AND SINGH 217
References Aldouse, J.R. 1972. Nursery Practice. Forestry Common
Bulletin. No. 43, London. Barnett, J.P. 1996. Moisture stress effects on
germination in longleaf and slash pine seeds. Forest Science 15: 275-276.
Bernstein, L. 1975. Effects of salinity and sodicity on plant growth. Annual Review of Phytopathology 13: 295-312.
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