Heterosis and Combining Ability Studies in Maize (Zea Mays L.).
A Diallel cross with 12 parents and resulting 66 F 1's were evaluated for heterosis and combining ability during 1987 and 1988. Differences among genotypes were significant for all characters. Genotype X Year interaction was significant for all traits except ear length. Average heterosis re...
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1991
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my-upm-ir.102922014-09-12T03:10:41Z Heterosis and Combining Ability Studies in Maize (Zea Mays L.). 1991 Reddy, Gillella Chinna A Diallel cross with 12 parents and resulting 66 F 1's were evaluated for heterosis and combining ability during 1987 and 1988. Differences among genotypes were significant for all characters. Genotype X Year interaction was significant for all traits except ear length. Average heterosis related to better parent was highest for plot yield, Kernel number per row, ear length and ear diameter. Heterosis was maximum in combinations involving parents of extreme grain type (dent X flint) and/or diverse geographical origin. Degree of heterosis was lowest in crosses of high yielding parents and vice-versa. SCA was relatively more important for all characters. Data on heterosis was in general agreement with variance component ratios of SCA and GCA and supported conclusions concerning the relative importance of SCA over GCA. Variance components for interactions involving SCA and years were consistently larger suggesting that SCA variance includes a considerable portion of genotype-environment interaction, apart from non-additive deviations. GCA effects were consistent from year to year while SCA effects were not. Graphical analysis on diallel data revealed that dominance and epistasis were important for most characters. A tendency of more number of dominant genes were associated with greater performance of characters (except plant and ear height) in the desirable direction. Most important yield components were ear diameter, ear length, number of kernels per row and lOOO-kernel weight. Yield components as well as maturity traits were positively interrelated among themselves, respectively. However, maturity characters were negatively correlated with most traits. Heritability estimates based on co-variance among relatives were generally in close agreement with estimates based on variance components confirming the results of combining ability analysis. Heterosis breeding, reciprocal recurrent selection or recurrent selection for SCA may be followed depending on the final objective. Heterosis Corn 1991 Thesis http://psasir.upm.edu.my/id/eprint/10292/ http://psasir.upm.edu.my/id/eprint/10292/1/FP_1991_5_A.pdf application/pdf en public phd doctoral Universiti Pertanian Malaysia Heterosis Corn Faculty of Agriculture English |
| institution |
Universiti Putra Malaysia |
| collection |
PSAS Institutional Repository |
| language |
English English |
| topic |
Heterosis Corn |
| spellingShingle |
Heterosis Corn Reddy, Gillella Chinna Heterosis and Combining Ability Studies in Maize (Zea Mays L.). |
| description |
A Diallel cross with 12 parents and resulting 66 F 1's were evaluated
for heterosis and combining ability during 1987 and 1988. Differences among
genotypes were significant for all characters. Genotype X Year interaction
was significant for all traits except ear length.
Average heterosis related to better parent was highest for plot yield,
Kernel number per row, ear length and ear diameter. Heterosis was maximum
in combinations involving parents of extreme grain type (dent X flint) and/or
diverse geographical origin. Degree of heterosis was lowest in crosses of high
yielding parents and vice-versa.
SCA was relatively more important for all characters. Data on heterosis
was in general agreement with variance component ratios of SCA and
GCA and supported conclusions concerning the relative importance of SCA
over GCA. Variance components for interactions involving SCA and years
were consistently larger suggesting that SCA variance includes a considerable portion of genotype-environment interaction, apart from non-additive deviations.
GCA effects were consistent from year to year while SCA effects were
not.
Graphical analysis on diallel data revealed that dominance and epistasis
were important for most characters. A tendency of more number of
dominant genes were associated with greater performance of characters
(except plant and ear height) in the desirable direction.
Most important yield components were ear diameter, ear length,
number of kernels per row and lOOO-kernel weight. Yield components as well
as maturity traits were positively interrelated among themselves, respectively.
However, maturity characters were negatively correlated with most traits.
Heritability estimates based on co-variance among relatives were
generally in close agreement with estimates based on variance components
confirming the results of combining ability analysis.
Heterosis breeding, reciprocal recurrent selection or recurrent selection
for SCA may be followed depending on the final objective. |
| format |
Thesis |
| qualification_name |
Doctor of Philosophy (PhD.) |
| qualification_level |
Doctorate |
| author |
Reddy, Gillella Chinna |
| author_facet |
Reddy, Gillella Chinna |
| author_sort |
Reddy, Gillella Chinna |
| title |
Heterosis and Combining Ability Studies in Maize (Zea Mays L.). |
| title_short |
Heterosis and Combining Ability Studies in Maize (Zea Mays L.). |
| title_full |
Heterosis and Combining Ability Studies in Maize (Zea Mays L.). |
| title_fullStr |
Heterosis and Combining Ability Studies in Maize (Zea Mays L.). |
| title_full_unstemmed |
Heterosis and Combining Ability Studies in Maize (Zea Mays L.). |
| title_sort |
heterosis and combining ability studies in maize (zea mays l.). |
| granting_institution |
Universiti Pertanian Malaysia |
| granting_department |
Faculty of Agriculture |
| publishDate |
1991 |
| url |
http://psasir.upm.edu.my/id/eprint/10292/1/FP_1991_5_A.pdf |
| _version_ |
1747811089339383808 |