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Fusarium wilt caused by F. oxysporum f. sp. ciceris causes extensive damage to chickpea (Cicer arietinum L.) in many parts of the world. In the central part of India, pathogen race 2 (Foc 2) causes severe yield losses. We initiated molecular marker-assisted backcrossing (MABC) using desi cultivar, Vijay, as a donor to introgress resistance to this race (Foc2) in Pusa 256, another elite desi cultivar of chickpea. To confirm introgression of resistance for this race, foreground selection was undertaken using two SSR markers (TA 37 and TA110), with background selection to observe the recovery of recurrent parent genome using 45 SSRs accommodated in 8 multiplexes. F plants were confirmed with molecular markers and backcrossed with Pusa 256, followed by cycles of foreground and background selection at each stage to generate 161 plants in BCF during the period 2009-2013. Similarly, 46 BCF plants were also generated in another set during the same period. On the basis of foreground selection, 46 plants were found homozygotes in BCF. Among them, 17 plants recorded >91% background recovery with the highest recovery percentage of 96%. In BCF also, 14 hybrid plants recorded a background recovery of >85% with the highest background recovery percentage of >94%. The identified plants were selfed to obtain 1341 BCF and 2198 BCF seeds which were screened phenotypically for resistance to fusarium wilt (race 2) besides doing marker analysis. Finally, 17 BCF and 11 BCF lines were obtained which led to identification of 5 highly resistant lines of Pusa 256 with Foc 2 gene introgressed in them. Development of these lines will help in horizontal as well as vertical expansion of chickpea in central part of India.

Greengram is an important protein-rich food legume crop. During the reproductive stage, high temperatures cause flower drop, induce male sterility, impair anthesis, and shortens the grain-filling period. Initially, 116 genotypes were evaluated for 3 years in two locations, and based on flowering, biomass, and yield attributes, they were grouped into four major clusters. A panel of 17 contrasting genotypes was selected for their heat tolerance in high-temperature greenhouses. The seedlings of the selected genotypes were exposed to heat shock in the range 37°C–52°C and their recovery after heat shock was assessed at 30°C. The seedlings of EC 398889 turned completely green and rejuvenated, while those of LGG 460 failed to recover, therefore, EC 398889 and LGG 460 were identified as heat-tolerant and heat-sensitive genotypes, respectively. Except for EC 398889, the remaining genotypes could not survive after heat shock. Fresh seeds of EC 398889 and LGG 460 were planted in field and pollen fertility and sucrose-synthase (SuSy) activity in grains were assessed at high temperatures. The pollen germination and SuSy activity were normal even at temperatures beyond 40°C in EC 398889 and high SuSy activity enabled faster grain filling than in LGG 460. The precise phenotyping demonstrated significant differences in the light-temperature response of photosynthesis, chlorophyll fluorescence imaging of quantum yield (Fv/Fm), and electron transport rate (ETR) between heat-tolerant (EC 398889) and heat-sensitive (LGG 460) genotypes. Molecular profiling of selected accessions showed polymorphism with 11 SSR markers and the markers CEDG147, CEDG247, and CEDG044 distinguished tolerant and sensitive groups of accessions.

Cultivation of the same varieties of mungbean and blackgram across different seasons and locations is constrained by their photo-and thermosensitive behaviour. Developing insensitive genotypes, which can fit well across all seasons, requires robust donors which would provide genes imparting this trait. This study was undertaken to identify such donors in the Vigna species. Forty-eight accessions belonging to 13 Vigna species and eight released cultivars were evaluated under natural field conditions. Among these, two accessions, viz. V. umbellata (IC251442) and V. glabrescens (IC251372) were found photo-and thermo-insensitive as these were able to flower and set pods at temperatures as high as 43.9°C and as low as 2.7°C. Pollen viability studies indicated viable pollen (>75% at 2.7°C and >85% at 41.9°C) and normal pollen tube growth at both the extremes of temperature. The identified V. glabrescens accession has long, constricted pods and dark green, mottled seeds while V. umbellata has smooth, curved pods and shining, oval, large seeds. Both these accessions can be utilized in developing photo-thermo insensitive genotypes in cultivated Vigna species.Key words: photo -thermo insensitivity -V. umbellata -V. glabrescens -wild VignaThe genus Vigna comprises more than 200 immensely variable species. Many of these are agronomically important and depict considerable economic and environmental importance. Amongare cultivated and consumed mostly in south and Southeast Asia and Africa. Many of the above species beside their high protein grains are valued as forage, green manure and cover crops. Mungbean and blackgram are the most popular and economically important crops of the Vigna group. India is the largest producer of these crops in the world and accounts for 65% of acreage and 54% of global production (Pratap et al. 2012). Keeping in view their short crop cycle, low input requirements and ability to survive in a wide range of adverse soil and climatic conditions, there is an ample scope of growing these crops across the seasons (spring, summer, winter and rainy seasons) in different parts of the country as a sole, relay or intercrop (Pratap et al. 2013). There is also a large scope of their further horizontal expansion in large areas, particularly in the rice fallows in peninsular India and in summer cultivation after the harvest of wheat, potato and rapeseed-mustard in Punjab, Haryana, Rajasthan and western Uttar Pradesh. However, the biggest hindrance in horizontal expansion of blackgram and mungbean in India is their photo-and thermo-sensitive nature which necessitates breeding of an array of genotypes for different agro-climatic zones of the country. Most of the varieties of mungbean and blackgram which have been bred till date are suitable only for a particular agro-climatic zone and cropping season. Nevertheless, most of the farmers usually recycle their seeds year after year and also across different seasons being unaware about the suitability of a particular variety in a specific season. In most of the...

Grain legumes, the important constituents of sustainability-based cropping systems and energy-limited vegetarian diets have long been the subject of scientific research. Tremendous technological strides were made in the so-called orphan crops, in terms of both varietal improvement and generation of basic information. Despite recalcitrancy and high genotype dependency, in vitro culture techniques such as organogenesis, in vitro mutagenesis, embryo rescue and in vitro gene transfer have been deployed for improvement of several grain legumes and these played an important role in introgression of desirable genes from related and distant species and creation of additional genetic variability. Stable and reproducible regeneration protocols resulted in the development of genetically modified chickpea, pigeon pea, cowpea, mungbean, etc., while embryo rescue was deployed successfully for recovery of interspecific recombinants, a few of them exploited for the development of commercial cultivars. Nevertheless, doubled haploidy witnessed limited success and protoplast regeneration and in vitro mutagenesis remained of academic interest.The present review focuses on the progress, achievements, constraints and perspectives of using in vitro technology in grain legume improvement.

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