Genetic Studies and Backcross Breeding for Shelf Life and Yield in Long Bean (Vigna Sesquipedalis (L.) Fruw)
A study was conducted on genetics of shelf life and yield characters of long bean. Four parental lines namely, L30, KU7, KU8 and CSL 1 9 were used in the study. Genetic component analysis for shelf life and yield characters were done following generation mean analysis from four cross combination...
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| Format: | Thesis |
| Language: | English English |
| Published: |
1997
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/10402/1/FP_1997_11_A.pdf |
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| Summary: | A study was conducted on genetics of shelf life and yield characters
of long bean. Four parental lines namely, L30, KU7, KU8 and CSL 1 9 were
used in the study. Genetic component analysis for shelf life and yield
characters were done following generation mean analysis from four cross
combinations namely Cross 1 (L30 X KU7), Cross 2 (L30 X KU8), Cross 3
(KU7 X KU8) and Cross 4 (L30 X CSL1 9). F1, F2 and backcross generations
were developed. A study was also conducted to transfer genes for long shelf
life from a donor parent (L30) to the genetic background of recurrent parent
(KU7, KU8, CSL 19) using backcross breeding method.
Results of scaling test showed that the additive-dominance model was
adequate in explaining the genetic control of seeds per pod, seed weight,
pod protein and seed protein in Cross 1; pod protein, seed protein and pod
protein yield per plant in Cross 2; and shelf life in Cross 4. This study revealed the importance of dominance gene effects, followed by dominance
X dominance (I) interaction effects for shelf life and yield characters. The
additive gene effect was proportionately small . Duplicate type of epistasis
was observed in most of the characters including shelf l ife. Exploitation of
heterosis breeding is suggested for the improvement of these traits having
involved with non-additive gene effects. For characters which are under the
control of additive (d) and additive X additive (i) gene interactions, simple
selection procedu re like pedigree method in the early generation is
recommended .
The varied estimates of narrow-sense heritability among the crosses
for different characters were due to genotype X environment interactions.
Estimates of narrow-sense heritability for pod yield per plant and shelf life
were high in Crosses 1 and 2, respectively. Shelf life and pod yield
manifested high estimates of narrow-sense heritability in Cross 4.
The degree of heterosis varied with characters among the crosses,
because of diverse geographical origin of the parental lines and the
contributions of background genotypes through its interaction with
segregating loci. Heterosis estimates were moderately h igh for shelf life and
pod yield per plant in Cross 1, and low in Crosses 2, 3 and 4. Days to flower,
days to harvest, moisture content and pod length showed negative heterosis
among the crosses, indicating earliness of the hybrids, having less moisture
content and reduced pod length . |
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