Inheritance of male sterility and development of new male sterile line in ridge gourd (Luffa acutangula (L.) Roxb.
Loading...
Files
Date
2011
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Olericulture, College of Horticulture, Vellanikkara
Abstract
The present study entitled “Inheritance of male sterility and development of new male sterile line in ridge gourd Luffa acutangula (L.) Roxb.” was undertaken in the Department of Olericulture, College of Horticulture, Vellanikkara during 2010-11. The objective of the study was to investigate the inheritance of male sterility in ridge gourd and to develop new male sterile line in ridge gourd using back cross generations of sterile hybrids. Study also aims in evaluating the performance of F1 hybrid, MS x Arka Sumeet for horticultural characters. Male sterile line is now maintained under in vitro condition. All the in vitro regenerated plants exhibited stability in the expression of male sterility.
F2 seeds resulted from the selfing of F1 hybrid, MS x Arka Sumeet was raised to study the expression of male fertility. Out of 106 plants raised in the F2 generation, 56 plants were male fertile and 50 plants were male sterile. There were observable differences between the male sterile and male fertile plants with respect to male flower production whereas female flowers in both types were similar. Chi square test was employed to test the goodness of fit and the 9:7 (fertile: sterile) complementary gene action ratio was found to be significant. The Chi square test suggested that two dominant genes might have certain interactions with cytoplasmic male sterility (CMS). Two dominant fertility restorer gene viz., Rf1 and Rf2 is now proposed for this model.
Assuming that MS line in ridge gourd is having a genotype, S (rf1rf1 rf2rf2) carrying both fertility restorer gene in homozygous recessive state and sterile cytoplasm, S, and Arka Sumeet possess a genotype N (Rf1Rf1 Rf2Rf2) carrying both fertility restorer gene in homozygous dominant state and normal fertile cytoplasm, N, F1 will be male fertile as the genotype of F1 is S (Rf1rf1 Rf2rf2). Here though F1 is inheriting a sterile cytoplasm from male sterile female parent, presence of both dominant fertility restorer gene, viz., Rf1 and Rf2 restores the fertility of F1. In F2, presence of both dominant fertility restorer gene in either homozygous or heterozygous condition ensures male fertility.
All three way crosses viz, (MS x Deepthi) x Arka Sumeet, (MS x IC-92685) x Arka Sumeet, (MS x IC-92671) x Arka Sumeet and (MS x CO2) x Arka Sumeet regained fertility indicating the presence of dominant fertility restorer gene in Arka Sumeet. The sterile hybrids on back crossing with respective pollen parents also exhibited male fertility at various stages of crop growth. Restoration of male fertility in BC1 generation indicate the unstable nature of sterile cytoplasm. F2 segregants producing fertile racemes during last stage of crop growth have more potential for evolving stable male sterile lines. Selective mating of these plants with male sterile plants or selfing can be advocated for developing new male sterile lines.
The F1 hybrid (MS x Arka Sumeet) exhibited significant heterobeltiosis for days to emergence of first female flower, node to first male flower, node to female flower, number of fruits per plant and yield per plant. High heterosis exhibited by the F1 hybrid (MS x Arka Sumeet) indicates the scope of exploiting the male sterile line in heterosis breeding. This is the first study which attempted to find out the inheritance of male sterility and fertility restoration in ridge gourd and is the first report of presence of cytoplasmic male sterility and dominant fertility restorer gene in cucurbits.
Description
PG
Keywords
null