Development and Commercialization of CMS Pigeonpea Hybrids

Abstract

The role of heterosis in enhancing productivity in food crops is well known. Legume breeders have not been able, however, to take advantage of this genetic phenomenon for a long time, due to biological restrictions, such as the requirement of high seeding rate and the inability to produce large quantities of F 1 hybrid seed. Recently, in pigeonpea (Cajanus cajan (L.) Millsp.), a breakthrough has been realized with the development and marketing of the world's first legume hybrid, ICPH 2671. The key for this achievement was breeding and using a stable cytoplasmic nuclear male sterility (CMS) system obtained from the cross between C. cajanifolius, a wild relative of pigeonpea, and the cultivated type. The inherent partial natural out-crossing of pigeonpea was knitted with this CMS system to facilitate economically-viable large-scale hybrid seed production. These developments provided opportunities to overcome the historic stagnant low yield (0.6-0.8 t ha-1) through heterosis breeding. Among hundreds of hybrid combinations tested, a cross between ICPA 2043 and ICPL 87119 (=ICPR 2671), designated as ICPH 2671, was the most promising, with >40% yield superiority (reaching yields above 3 t ha-1) over the prevalent cultivar 'Maruti', in multi-location, multi-year, on-station trials, as well as on-farm evaluations. The outstanding performance of ICPH 2671 led to its release in 2010 as the first medium duration commercial pigeonpea hybrid in India. Subsequently, two additional pigeonpea hybrids, ICPH 3762 and ICPH 2740 were also released

Maternal inheritance of male sterility in the progeny of a natural hybrid between Cajanus lineatus and C. cajan

“…Since at present the entire hybrid breeding programme is based on a single (A 4 ) cytoplasm (Saxena et al., ), the cytoplasmic uniformity may pose some problems in future with respect to productivity and adaptation of hybrids. Such a situation may arise if the mitochondrial genome of A 4 cytoplasm harbours gene(s) for any serious disease, insect or abiotic stress.…”

“…A breakthrough in this direction, however, was achieved when a stable CMS system was bred (Saxena, Kumar, Srivastava, & Shiying, ) in a partially cross‐pollinated legume pigeonpea or red gram ( Cajanus cajan [L.] Millspaugh). At present, three commercial pigeonpea hybrids are under cultivation in India; and these are based on a single (A 4 ) cytoplasm (Saxena, Sharma, & Vales, ). Such a cytoplasmic uniformity needs to be avoided in a long‐term hybrid pigeonpea breeding programme.…”

Origin of early maturing pigeonpea germplasm and its impact on adaptation and cropping systems

“…Moreover, these early maturing hybrids and their parental materials have recently been shared with the interested public and private seed companies for further testing, promotion and adoption of hybrids. The technology details related to hybrid breeding, commercial seed production and adoption have been discussed in length by Saxena, Sharma, and Vales ().…”

Can pigeonpea hybrids negotiate stresses better than inbred cultivars?

“…As a result, its productivity is low (700 ± 100 kg/ha). To enhance its yield, breeders developed a CMS-based hybrid pigeonpea technology ( Saxena et al 2018 ). During this process a number of yield trials involving experimental hybrids were conducted in diverse environments and, in spite of various types of local stress conditions, the hybrids convincingly out-performed the inbred cultivars.…”