HETEROSIS BREEDING FOR CROSSING PRESENT YIELD BARRIERS IN COTTON
Mar 13, 2017

Breeding & Genetic improvement WCRC Breeding-Asia WCRC1
Abstract                                                                         Back to Table of contents

India is the first country in the world to commercially exploit the phenomenon of heterosis in cotton.  At present 27% of the total area under cotton in India is grown under hybrids but their share of total cotton production is more than 40%.  In India, the cultivation of hybrids remained restricted to central and southern cotton zones since no hybrid was successful under north Indian conditions.  The long-duration hybrids were not suitable under the double cropping system (cotton-wheat rotation) followed in the Punjab and the northern zone.  The heterosis breeding work got impetus with the development of short duration, high yielding varieties like LH886, F846, LH900 and F1054 and the sanctioning of a hybrid project by the Indian Council of Agricultural Research in 1989.  Concerted efforts were made for the development of early maturing and high yielding intra hirsutum hybrids suitable for Punjab conditions.  From 1989 to 1993 a total of 535 hybrids have been developed by hand emasculation and hand pollination and evaluated in different trials in the state.  Intra-hirsutum hybrids identified were: LHH107, LHH121, LHH144, LHH212, LHH185, LHH315, LHH332, LHH468, LHH505, LHH565, LHH601 and LHH608.  These hybrids possess high yield potential and short duration and are suitable under a cotton-wheat rotation.  An intra-hirsutum hybrid 'Fateh' has been recommended by the Punjab Agricultural University in 1993 and hybrids LHH107, LHH121 and LHH 144 are at advanced stages of evaluation.  The hybrids identified for Punjab conditions combine earliness (170-175 days to maturity), big boll size (5.0 g) monopodial plant habit (1-5 monopods), superior fibre quality characters (2.5% span length more than 26 mm), tolerance to sucking pests and seed cotton yield 40% higher than varieties.

Conclusion

Heterosis breeding offers considerable opportunity for increasing productivity of cotton in the world. The observed heterosis of over 150% in test cross nurseries over check varieties and more than 50% commercial heterosis in replicated multi row multilocation trials conducted at Punjab Agricultural University have demonstrated the potential of hybrids over high yielding varieties.  Heterosis is maintained even under stress environments, especially rainfed farming.  Productivity of cotton in India has increased 112% since the release of the first cotton hybrid H4 in 1970. However success in hybrid cotton is not easy. The seed production technology has to be perfected to make it economically feasible by using cytoplasmic and genetic male sterility systems and by regional/international cooperation. The promotion of heterosis breeding in cotton to meet the future challenges for increasing fibre production and to provide clothing to the ever increasing human population should be given high priority.

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