GENETIC ANALYSIS OF GRAIN YIELD, ITS CONTRIBUTING CHARACTERS AND STEM BORER RESISTANCE IN MAIZE (Zea mays L.)
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Date
2022-07-02
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PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY
Abstract
The present investigation “Genetic analysis of grain yield, its contributing
characters and stem borer resistance in maize (Zea mays l.)” had been undertaken in
maize to carry out the combining ability analysis and to estimate heterosis as well as to
understand nature of gene action for grain yield, its contributing characters and
components which contribute to stem borer resistance. Character association, G X E
interaction and stability of experimental hybrids for yield and yield components was
studied. The data was collected on days to 50 per cent tasseling, days to 50 per cent
silking, days to maturity, plant height (cm), ear height (cm), ear girth (cm), ear length
(cm), number of kernel rows per ear, number of kernels per row, 100-kernel weight (g)
shelling percentage, grain yield per plant leaf injury rate and dead heart percentage.
Twenty seven diverse maize genotypes were screened for their reaction to maize
stem borer, Chilo partellus under artificial infestation during Kharif, 2018. Out of the 27
inbred lines screened under artificial infestation, three were found to be resistant to
Chilo partellus with leaf injury rating (LIR) score less than 3.0, while 13 were
moderately resistant and 11 were highly susceptible.
Based on reaction to C. partellus, eight parents were selected and crossed in a
diallel fashion excluding reciprocals (Griffings method-II, model-I) during Rabi 2018-
19 and the resulting 28 crosses along with 8 parents and 3 checks, viz., NK-6240 ,
DHM-117 and CMH-8-287 were evaluated in Randomized Block Design with three
replications at three locations viz., Rudrur, Rajendranagar and Hyderabad during kharif,
2019 and the same 28 single crosses along with parents were screened against Chilo
partellus under artificial infestation condition simultaneously at Winter Nursery Centre,
Rajendranagar, Hyderabad during kharif, 2019 and F2 generation of one cross (resistant
× susceptible combination) was evaluated against Chilo partellus during kharif, 2020.
The pooled analysis of variance for combining ability revealed significant
differences due to environments, parents, hybrids and various interactions indicating the
existence of wider variability in the material studied. The ratios of GCA/SCA variances
revealed preponderance of non-additive gene action for all of the traits favouring for the
exploitation of heterosis breeding. Combining ability analysis revealed that among the
parents, CM-139 and DMRDMRE-63 were found to be good general combiners for
earliness viz., days to 50 per cent tasseling, days to 50 per cent silking and days to
maturity. While,The parents Bio-688, BML-6 and DML-1432 were found to be good
general combiners for grain yield and other its directly related traits. These parents had
resulted in the production of superior single crosses BML-6 × PFSR-46, BGS-337 ×
Bio-688, Bio-688 × PFSR-46 and BML-6 × Bio-688 for grain yield per plant. Hence,
these inbred lines have potential application in the crop improvement programmes.
High specific combining ability effects for grain yield per plant were noticed in
the cross combinations BML-6 × PFSR-46, BGS-337 × Bio-688, Bio-688 × PFSR-46
and BML-6 × Bio-688 which can be considered as good specific combiners and
genetically worthy crosses as they were superior for yield and important yield
contributing characters.
The hybrid BML-6 × PFSR-46 recorded significant positive standard heterosis
over three standard checks CMH-8-287, NK-6240 and DHM-117. The highest standard
heterosis for grain yield per plant was recorded for hybrids BML-6 × PFSR-46, BML-6
× Bio-688 and BGS-337 × Bio-688 along with per se and high sca effects. These
hybrids may be further exploited in multilocation evaluation over seasons before
releasing them for commercial cultivation.
Results of stability analysis revealed that three hybrids viz., BML-6 x Bio-688,
Bio-688 × Saf91x2#7 and BML-6 × Saf91x2#7 are identified as stable and best
performing hybrids with grain yield 196.14 g, 181.04 g, 170.37 g per plant hence,
suitable for wider environments.
The investigation on correlation suggesting that selection of promising
genotypes for ear length, plant height, ear height, ear diameter, number of rows per
kernel, number of kernels per row and 100 kernel weight may be accompanied by
increasing grain yield of maize as they had highly significant positive association with
grain yield. The path coefficient analysis clearly emphasized the need for selection of
ideal genotypes with greater number of kernels per row, ear length, shelling percentage,
100 kernel weight, ear height and number of kernel rows per ear as these were found to
be the important traits with direct effect on grain yield.
Based on combining ability studies on components that contribute to resistance
to spotted stem borer, Chilo partellus, among the parents, DMRE-63, Saf91×2#-7 and
Bio-688 were good general combiners for stem borer resistance as they exhibited
negative gca effects for leaf injury rate and dead heart percentage. While the hybrids,
BML-6 × Bio-688, CM-139 × PFSR-46, CM-139 × BML-6, BGS-337 × BML-6, PFSR 46 × DMRE-63 and BML-6 × Saf91×2#-7 were good specific combiners for stem borer
resistance as they exhibited negative sca effects for both the studied traits. The F2
population study of cross, BML-6 × DMRE-63 (Susceptible × Resistance) indicated a
monogenic dominant gene inheritance for leaf injury rate in the cross BML-6 × DMRE 63 (Susceptible × Resistance), which needs to be further verified through F3 population
study.
Keeping in view of the above facts, by considering all factors like per se
performance, sca effect, standard heterosis and stability the most promising hybrids
identified were BML-6 × Bio-688, BML-6 × PFSR-46, BGS-337 × Bio-688 and Bio 688 × Saf91×2#-7 in which, BML-6 × Bio-688 and Bio-688 × Saf91×2#-7 were least
susceptible to stem borer. These identified promising cross combinations are to be
tested extensively over different agro climatic zones and across the years for their
superiority and stability before commercial release and were may be advanced for
selfing for the isolation of transgressive segregants or homozygous lines for use in
breeding programmes.The present investigation “Genetic analysis of grain yield, its contributing
characters and stem borer resistance in maize (Zea mays l.)” had been undertaken in
maize to carry out the combining ability analysis and to estimate heterosis as well as to
understand nature of gene action for grain yield, its contributing characters and
components which contribute to stem borer resistance. Character association, G X E
interaction and stability of experimental hybrids for yield and yield components was
studied. The data was collected on days to 50 per cent tasseling, days to 50 per cent
silking, days to maturity, plant height (cm), ear height (cm), ear girth (cm), ear length
(cm), number of kernel rows per ear, number of kernels per row, 100-kernel weight (g)
shelling percentage, grain yield per plant leaf injury rate and dead heart percentage.
Twenty seven diverse maize genotypes were screened for their reaction to maize
stem borer, Chilo partellus under artificial infestation during Kharif, 2018. Out of the 27
inbred lines screened under artificial infestation, three were found to be resistant to
Chilo partellus with leaf injury rating (LIR) score less than 3.0, while 13 were
moderately resistant and 11 were highly susceptible.
Based on reaction to C. partellus, eight parents were selected and crossed in a
diallel fashion excluding reciprocals (Griffings method-II, model-I) during Rabi 2018-
19 and the resulting 28 crosses along with 8 parents and 3 checks, viz., NK-6240 ,
DHM-117 and CMH-8-287 were evaluated in Randomized Block Design with three
replications at three locations viz., Rudrur, Rajendranagar and Hyderabad during kharif,
2019 and the same 28 single crosses along with parents were screened against Chilo
partellus under artificial infestation condition simultaneously at Winter Nursery Centre,
Rajendranagar, Hyderabad during kharif, 2019 and F2 generation of one cross (resistant
× susceptible combination) was evaluated against Chilo partellus during kharif, 2020.
The pooled analysis of variance for combining ability revealed significant
differences due to environments, parents, hybrids and various interactions indicating the
existence of wider variability in the material studied. The ratios of GCA/SCA variances
revealed preponderance of non-additive gene action for all of the traits favouring for the
exploitation of heterosis breeding. Combining ability analysis revealed that among the
parents, CM-139 and DMRDMRE-63 were found to be good general combiners for
earliness viz., days to 50 per cent tasseling, days to 50 per cent silking and days to
maturity. While,The parents Bio-688, BML-6 and DML-1432 were found to be good
general combiners for grain yield and other its directly related traits. These parents had
resulted in the production of superior single crosses BML-6 × PFSR-46, BGS-337 ×
Bio-688, Bio-688 × PFSR-46 and BML-6 × Bio-688 for grain yield per plant. Hence,
these inbred lines have potential application in the crop improvement programmes.
High specific combining ability effects for grain yield per plant were noticed in
the cross combinations BML-6 × PFSR-46, BGS-337 × Bio-688, Bio-688 × PFSR-46
and BML-6 × Bio-688 which can be considered as good specific combiners and
genetically worthy crosses as they were superior for yield and important yield
contributing characters.
The hybrid BML-6 × PFSR-46 recorded significant positive standard heterosis
over three standard checks CMH-8-287, NK-6240 and DHM-117. The highest standard
heterosis for grain yield per plant was recorded for hybrids BML-6 × PFSR-46, BML-6
× Bio-688 and BGS-337 × Bio-688 along with per se and high sca effects. These
hybrids may be further exploited in multilocation evaluation over seasons before
releasing them for commercial cultivation.
Results of stability analysis revealed that three hybrids viz., BML-6 x Bio-688,
Bio-688 × Saf91x2#7 and BML-6 × Saf91x2#7 are identified as stable and best
performing hybrids with grain yield 196.14 g, 181.04 g, 170.37 g per plant hence,
suitable for wider environments.
The investigation on correlation suggesting that selection of promising
genotypes for ear length, plant height, ear height, ear diameter, number of rows per
kernel, number of kernels per row and 100 kernel weight may be accompanied by
increasing grain yield of maize as they had highly significant positive association with
grain yield. The path coefficient analysis clearly emphasized the need for selection of
ideal genotypes with greater number of kernels per row, ear length, shelling percentage,
100 kernel weight, ear height and number of kernel rows per ear as these were found to
be the important traits with direct effect on grain yield.
Based on combining ability studies on components that contribute to resistance
to spotted stem borer, Chilo partellus, among the parents, DMRE-63, Saf91×2#-7 and
Bio-688 were good general combiners for stem borer resistance as they exhibited
negative gca effects for leaf injury rate and dead heart percentage. While the hybrids,
BML-6 × Bio-688, CM-139 × PFSR-46, CM-139 × BML-6, BGS-337 × BML-6, PFSR 46 × DMRE-63 and BML-6 × Saf91×2#-7 were good specific combiners for stem borer
resistance as they exhibited negative sca effects for both the studied traits. The F2
population study of cross, BML-6 × DMRE-63 (Susceptible × Resistance) indicated a
monogenic dominant gene inheritance for leaf injury rate in the cross BML-6 × DMRE 63 (Susceptible × Resistance), which needs to be further verified through F3 population
study.
Keeping in view of the above facts, by considering all factors like per se
performance, sca effect, standard heterosis and stability the most promising hybrids
identified were BML-6 × Bio-688, BML-6 × PFSR-46, BGS-337 × Bio-688 and Bio 688 × Saf91×2#-7 in which, BML-6 × Bio-688 and Bio-688 × Saf91×2#-7 were least
susceptible to stem borer. These identified promising cross combinations are to be
tested extensively over different agro climatic zones and across the years for their
superiority and stability before commercial release and were may be advanced for
selfing for the isolation of transgressive segregants or homozygous lines for use in
breeding programmes.