EFFECT OF ENVIRONMENTAL FACTORS ON CORRELATION COEFFICIENT BETWEEN DIFFERENT MORPHOLOGICAL PARAMETERS OF
YIELD IN LINSEED (LINUM USITATISIMUM L.)
G.C. SRIVASTAVA, D.P.S. TOMAR, P.S. DESHMUKH AND R.B. MEHRA
Division of Plant Physiology, Indian Agricultural Research Institute New Delhi 110012
Revised, June 23, 1980'"
SUMMARY
Statistical studies of some yield components of 22 cultivars of linseed grown under irrigated and unirrigated field conditions were undertaken in order to obtain values of phenotypic and environmental correlation coefficients. Eleven out of a total of 55 correlations were found to have significant environmental association under irrigated condition and four of these i.e. boll on main shoot v., seed/boll, days to flo wer v., number of secondary branches, non fertile bolls V., height at which branching appeared and seed weight per plant v., primary branches were negative. When this behaviour was studied under un irrigated condition, the only correlation i. e. between seed weight per plant v., primary branches per plant retained its sign. The results clea rly highlight the important role, the environment plays on yield and their correlations.
INTRODUCTION
Linseed shows variation in yield when grown under different agroclimatic conditions namely Indogangetic belt (irrigated) and peninsular area (unirrigated) (Dastur & Bhatt 1965, Dybing, 1964). It was therefore felt necessarY to obtain some information on tlte association of different yield components with their relative contribution to seed yield under the two sets of environmental condition. Genetic correlations have been worked out in linseed mostly in a single environment (Joshi et
al., 1961, Jeswani & Murty, 1963). However, the utility of estimates of correlations
becomes limited unless the genotypes are grown in more than one environment. The present experiment was therefore undertaken to find out the association of yield component with yield under irrigated and unirrigated field conditions.
MATERIALS AND METHODS
Twenty two cultivars of linseed grown in different parts of the country were chosen for this experiment. They were NP (RR) 45,BS 12,BS 44, Neelum. Heera,
98
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·~
" ,,' -. .:. . • . .i
G. C. SRIV A!!TAVA, D. P. S. TOMAR, P. S. DESHMUKU AND It. B. MEURA
Mukta, T397, BR-2, LC-5, LC-122, Bengal 23, Mahoba local, R-17, EB~3.
M-10 S-36, Sholapur-A, Sabour T 6, NP (RR) 37, NP 18, NP 20 and Raipur white. Seeds were sown in two sets of environment in field plots having a size of 3x2 m in a randomised block design with three replicates at a row to row distance of 30 cm and plants spaced at 10 cm within the row. One set of plots was irrigated as and when required whereas the other plots were left unirrigated· till harvest. Data were collected on days to flower, yield and other components such as number of primary and secondary branches height at which branching appeared, stem dry weight, number of bolls on primary branches, boJJ weight, number of bolls on main shoot, number of nonfertile bolls, number of seeds per boll and seed weight per plant.
Correlation coefficients were computed on IBM 1620 computor at the Institute of Agricultural Research Statistics, New Delhi.
RESULTS AND DISCUSSION
The variabilty in eleven characters and correlation coefficient between different characters studied among twenty two cultivars grown under irrigated and unirrigated
conditions are reported in table I, II, & III.
It may be stated that there were significant differences among the twenty two
cultivars for all the eleven characters. The Phenotypic correlations among eleven characters reported in table II revealed that under the irrigated condition, all but one of the correlation coefficients were significant, the only nonsignificant correlation being the one between the primary branches per plant and the days taken. to flower. Under the unirrigated condition, all the correlations were
found to be ~ignificant at one per cent level of significance.
With an objective of studying the effect of environment, those characters which showed association both at the phenotypic level and environmental level, and those which showed association only at the phenotypic level, were separated under both sets of enviromental conditions (table III). Only eleven out of 55 correlations were found to have significant environmental association under the ir.rigated condition. Out of eleven, four associations were found to be negative. They were:
(i) Number of bolls on main shoot per plant v., seeds/boll (ii) Days taken to flower
v., height at which branching appeared (iii) Nonfertile bolls/per plant v., height at which branching appeared (iv) Seed weight/plant v., primary branches/plant.
When the behaviour of these correlations under unirrigated condition was studied, it was found that the only correlation between seed weight/plant v., primary branches per plant retained its sign. This implied that environmental factores other than the application or otherwise of irrigation were responsible for this correlation and these primarily were responsible for a reduction in seed weight whenever the number of primary branches increased. Two correlations namely :_
·'""":" ,---"'-"'~'" .""""""","~~---"----" ," Table 1. Analysis of variance for eleven characters in linseed under irrigated and unirrigated conditions (Figures without parantheses refer to irrigated and those with parantheses refer to unirrigated conditions) . df Seed wtl No. of non No. of bolls No. of Days No. of Boll wt. No. of No. of Ht. at Stem plant fertile bolls/ on main primary taken seeds/ per plant bolls on second which wt/ (g) plant shoot/plant branches to boll (g) p.imary ary bran- branch-plant per flower branch-chesl iog appe-(g) plant openin, es/plaDt plant ared (cm)
i
!'!1 Replication 2 480.65 566.09 330.80 24.04 873.57 173.6 252.3 47.8 213.6 241.4 469.7 (2) (524.9) (708.2) (44.8) (32.0) (162.4) (231.0) ( 185.1) (263.3) (494.0) (245.5) (344.9) Variety 20 1715.6* 1033.90* 1391.10* 1787.4* 1688.5'" 2790.7*a:
2479.3· 1175.4* 1192.5* 1603.6· 1226·9* m (21) (997.4* (1342.8"') (1352.0"') (1189.9·) (2499.4·) 2592.7"') (1328.0·) 1667.7·) (2009.7.) (1872.7·) (1711.8.);!
% Error 40 327.2 392.7 344.2 300.7 338.5 154.7 252.2 376.1 383.3 467.4 221.1 I'" (42) (225.6) (315.2) (319.1) (169.8) (176.5) (181.4) (374.4) (375.1) (383.3) (201.3) (15S.0)~ n
*Si,nificant
at
S%
level
~
{4~
~
~Z
I'"i
~
~"----~=_'c"~·
.~,~,",~'~
Table 11. Phenotypic correlations between eleven characters of linseed under irrigated and unirrigated conditions (Figures without parentheses refer to irrigated and those with parentheses refer to unirrigated conditions)
g
No. of non No. of No. of Days No. of Boll wt. No. of No. of Heisht Stem WI. fertile boll/ boll on primary taken seeds/ per bolls on secondry at which per ~ plant main branches to boll plant primary bradches/ branchilll plant ~ shoot I per plant flower (I) branches/ plant appeared (I) plant opening plant· (cm)=
-
~ enSeed wt/plant 0.894"'''' 0.471"'''' 0. 879"'''' 0.130"'''' 0.760"'''' 0.878"'''' 0.613"'''' 0.542"'''' 0.786"'''' 0.8S6"''''
;!
(0.719"'''') (0.778"'.) (0.674·"') (0.176"'·) (0.602"'·) (0.819··) (0.73S··) (0.726"'''') (0.772"'·) (0,S03") No. of non fertile 0.6S2"'''' 0.8S0"'· 0.387" 0.828" 0.803·'" 0.707·· 0.768"'· 0,860" 0.698"~
bolls plant (0.633"'''') (O.SOS" (0.738"'·) (0.739··) (0.761"'''') (0.704··) (0.7S6"'''') (0.610·"').
0,
No. of bolls on 0.409·'" 0.S34" 0.4S6"'· 0.448"'· O.SIS"'''' 0.778"'''' 0.S6S"'''' 0.482'· !'C' main shoot/plant (0.399··) (0.740") (0.844·"') (O.68~"') (0.838··) (0.800"'''') (0.720'·) ~ No. of primary 0.197"'''' 0.799·· 0.66S"'''' 0.S43"'· 0.477·' 0.779" 0.661" ~ branches per plant (0.477·"') (0.399"'r) (0.646"'''') (0.520"'·) (0.S9S") (0.S2S"'·) ill: Days taken to flower 0.2S7·· 0.196" 0.S74"'· 0.S46""~
0.423""" 0.127"'''' open ins (0.81S"'''') (0.668"'''') (0.777U) (0.804 •• ) (0.743"'·) !'C' No. of seeds/boll 0.687'· 0.420'''' 0.637·'" 0.860·· 0.6S7"'·.
(jI (0.8S4"'''') (0.916"'''') (0.871""") (0.680 U )Ii
eni
"'" .. _, .. , ....•
_---,.
.
~ .. ,. ,. ,,~-.---.,-.-. ---,..~ Table III. Environmental correlations between eleven characters of linseed under irrigated and unirrigated conditions. (Figures without parentheses refer to irrigated and those within parenthesis refer to unirrigated conditions) No. of non No. of No. of Days No. of Boll No. of No. of HeIght Stem weight fertile boll/ bolls on primary takeD. seeds/ weight bolls on secondary at which per plant plant main shoot/ baranches/ to boll per primary branches/ branching plant plant flower plant branches/ plant appeared l'!1 opening (g) plant (em) Z...
Seed wt./Plant No. of non fertilebolls/l'lant No.
of
bolls
on
main
-0.070 (0.129)
0.226
(0.022) 0.110 (0056)
-0.480* (0.288+) -0.0 (0.240) -0.051
0.313
(-0.173) -380.180 (0.037)
-0.113 0.005 0.039 0.232 (-0.355*) 0.170 0.126 (0.227) (0.170) -0.331* -0.172 0.081
-(0.040) -0.156 (0.415··) -0,064
-0.206
(-0.291+)
0.544·*
(-0.200) -0.020 -0.026 (0.180)
-0.258+
(-0.290+)
0.057
0.445-·
(0.277+)
0.112 0.354·
~
z
a:: Mil Z >-4 > t'"shoot/plant No.
of
primary
branches/plant
(0.113)
(0.097) 0.155
(-0.064) (0.413*) (·0.200) 0.126 -0.012 (0.1l9) (-0.263+)
(0.206) 0.245 (0.017) (0.191) 0.435*· (0.180) (0.192) 0.279*
(-0.219)
0.241
~ (")
a
~Days taken to 0.321* 0.073 0.179 -0.738* 0.135 0.212 flower opening No. of seeds per boll (-0.1l6)
(0.050) 0.026 (0.039) (0.052) 0.021 (0.238) (0.043) 0.102
(-0.462··)
(-0,102) -0:045 (0.177)
-0,090
~
:s
t'%! t'" '='Boll weight per plant 0.215 0.057 -0.202 -0.213
....
No. of bolls on primary branches/plant (0.284+) ( -0.313*) 0.004 (0.200) (-0.118) 0.229 (0.092) 0.223Z t'"'
-
z
{;!l t'%!0.178
0.212
l"l! '='
102 G. C. SRIVASTAVA, D. P. S. TOMAR, P. S. DESHMUKH AND R. B. MEHRA
(b) Non fertile bolls per plant v., height at which branching appeared.
which showed a negative value under irrigated condition became non signifi. cant when irrigation was not applied. This indicates that these associations were mostly of physiological nature and subject to change by environmental factores.
When plants were irrigated, this lead to an increase in the secondary branches and early flowering. Similarly, when branching started earlier, this lead to more non fertile bolls. But under unirrigated condition, no such associations are abserved at environmental level.
The association of the bolls on main shoot/plant v., seeds/boll, which was negative under irrigated condition became positive under unirrigated condition. Under unirrigated condition, plants donot have more of secondary branches and the larger
the main shoot, the more is the number of seeds/boll. This seems to be a compansa
J
tory mechanism of the genotypes to retain as much fitness under unirrigated condition as possible, whereas under irrigated condition, the possibility of getting a large· number of seeds is by large number of bolls on the primary and secondary branches.
A similar observation has been noted by Blackman and Bunting (1951, 1955).
1
Under the irrigated condition following pairs of characters showed to have positive association:
1. Seed weight/plant v., stem weight/plant.
2. Non fertile bolls/plant v., secondary branches/plant. 3. Bolls on main shoot/plant v., dry weight/plant. 4. Primary branches/plant v., secondary branches/plant. 5. Days to flower v., seed/boll.
6. Primary branches/plant v., height at which branching appeared. 7. Height at which branching appeared v., dry weight/plant.
~
Out of these seven associations, the values for numbers 3,6 and 7 were not
available ~nder unirrigated conditions. Association 1 retained the positive sign
I
under both conditions, indicating that factores other than irrigation were responsible for this association. Association 2,4 and 5 changed to non significant under unirrigated condition. The disappearance of significant association of 2 may be explained in view of the fact that under unirrigated condition plants are having less number of sec ondary branches and with application of irrigation the number of secondary branches increases. Similar is the case with the number of non fertile boJls per plant. But under the unirrigated condition, the secondary branching has no correlation with bad bolls.
Correlation No 4 is also explainable. With irrigation the primary and secon dary branches increase whereas under unirrigated condition the secondary branches are affected. The correlation No 6 suggests that under irrigated conditions some physiological factores are playing a role in that larger the height, more the number of
primary branches. But this association is not Obsel vable under un irrigated condition.
1
ENVIRONMENTAL FACTORS ON YIELD IN LINSEED 103
It thus appears that unirrigated condition gives rise to some associations which are not seen under irrigated condition and these are mostly negative associations listed below:
I. Seed wtfplant v., boll wt/plant.
II. Seed wt/plant v., secondary branches/plant.
III. Non fertile bons/plant v., height at which branching appeared. IV. Primary branches/plant v., boll wt/plant.
V. Seed/boll v., secondary branches/plant.
VI. Boll wt/plant v., no. of bolls on primary branches/plant, VII. Boll wt/plant v., secondary branches/plant.
Two positive physiological associations were:
(i) Non fertile bolls/plant v., no.olbolls on primary branches/plant.
(ii) Bolls on main shoot/plant v., seeds/boll.
This study thus shows how strongly and important environmental factor like irrigation affects the correlation coefficients between yield components in case of linseed. It also shows, how some of the correlation coefficient values established by previous authors are invalidated by changing the environment under which the study is undertaken.
ACKNOWLEDGEMENTS
Authors are grateful to the Head, Division of Plant Physiology for providing necessary experimental facilities.
REFERENCES
Dastur, R.H. and Bhatt, J.O. (1965). Factors affecting the growth and yield of linseed (Linum
usitatisimum) in Malwa, Madhya Pradesh. Ind J. Agri. Sci., 35(2): 141-52.
Dillman, A.C. and Hopter, J.H.(1943). Effect of climate on the yield and oil content of flax seed and
on the iodme number oflinseed oil. U.S. Dept Agri. Tech Bull 884 : 1-69
Orbing, C.D.(1964). Influence of nitrogen on flax growth and oil production in varied environments.
Crop Sci., 4: 491-94.
Blackman, O.B. and Bunting, B.8.(1951). Studies on the oilseed crops I. Factors contributing seed
production in linseed. J. Agri. Sci., 41 : 256-70.
Jeswani, L.M. and Murty, B.R:(l963). Components of association between some of yield factors
in linseed Ind J. Gen. PI. Br'J 23(2): 163-75 .
• Joshi, A.B. Ramanujam, S and Pillay, P.N.C.(1961). Breeding for quantitative characters in linseed
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