BP Singh

Promising Introductions and Prioritize Needs for Exotic Germplasm 95heterosis with respect to early and high yields should also beintroduced to increase the yield of hybrids.In soybean, germplasm resources having high protein and oilcontent, resistant/ tolerant to acidic and saline soils and cytoplasmicmale sterile lines for exploitation of hybrid vigour need to beintroduced on priority.Fibre cropsCotton: In the last four decades, Gossypium hirsutum cottons havereplaced desi cottons in 30 lakh ha under rainfed conditions. Byand large, the desi cotton cultivation in the rainfed conditions is'now confined primarily to dry and unproductive areas, which isa major cause for low productivity. Three major possibilities tobring about a rapid breakthrough in rainfed cotton productivitymust include: (i) evolution of new plant ideo types in desi andAmerican cottons, (ii) development of superior hybrids withmedium staple and short duration and (iii) incorporation ofretPstance factors from various sources.(a) Ideal new plant types : Breeding for a new plant type forrainfed conditions is just gaining momentum, but it is yet to takeproper shape. The appropriate genotype would be the one that hasa reduced duration and near determinate type with high bollbearing potential so as to minimize the risks and losses arisingfrom environmental adversities and lapses in management.Diminutive plant type, both in structure and stature with compactzone of fruiting having even a semic1uster fruiting habit, reasonablylarge bolls, fruiting at a lower node on main stem and endowedwith other components of yield, earliness and resistance are likelyto be more useful. In desi cottons, evolution of these kinds of planttypes would need developmental breeding for establishment ofsuch basic forms for plant stature, bigger boll size than at presentand early maturity before taking up recombination breeding. Butin G. hirsutum the required components have already beenidentified.(b) Hybrid cottons: The cultivation of hybrid cottons commencedin the seventies in India and now widely practiced in 10-12% ofthe total cotton area. Till today hand emasculation and handpollination have proved to be the only way of producing hybddcotton seeds for commercial cultiyation and the cost per kg of seedto the farmer is exhorbitant.