Achievements and Present Status: The crops on which research is being done at BINA are: chickpea (Cicer arietinum L.), mung bean (Vigna radiata (L.) Wilczek), black gram (Vigna mungo (L.) Hepper). lentil (Lens culinaris Medic), and khesari (Lathyrus sativus L.). The achievements in the breeding efforts of these crops during the last 8 years have been summarized by Shaikh (1988) and are mentioned below. 1. Identification of yield components with a high contribution. 2. Determination of coefficient of variability for these characters and the scope for their improvement. 3. Establishment of correlation among the components. 4. Collection, screening, and evaluation of germplasm of local and exotic origin, and selection of superior genotypes. 5. Induction of mutations through treatment with physical and chemical mutagens, and selection and development of superior genotypes. 6. Utilization of mutants in hybridization with other mutants and with adapted cultivars.
Chickpea: The number of pods and branches plant-1 were found to have a positive correlation with seed yield (Ahmed et al. 1986). Partial and multiple correlation studies also revealed a positive correlation between the number of pods and seed yield. These studies suggested that the number of pods should be considered the best selection criterion. Treatment of the chickpea cultivar Faridpur 1 seeds with 20 kR gamma rays (60 Co) and subsequent selection of a mutant, M 669, superior in yield and protein content led to the identification of cultivar Hyprosola (Shaikh et al. 1982). It has more pods and seeds plant-1 and a higher harvest index. The slightly (10%) smaller seed size of the mutant compared to Faridpur 1 is more than offset by the increased number of seeds thereby increasing the total seed yield. Protein content in M 669 was 22.5% compared to 18.5% in the parental cultivar. The mutant has relatively more field tolerance to pod borer (Shaikh et al. 1982), and Altemaria leaf spot and also improved nodulation and better symbiosis with Rhizobium local strain No. TLS (Poddar et al. 1980). The mutant was released in 1982 and named Hyprosola (High-yielding-high protein chickpea). Oram et al. (1987) studied the isozyme similarity and genetic differences in morphology between Hyprosola and Faridpur 1 and indicated the presence of a few recessive mutant alleles in Hyprosola. These were alleles for small seeds (ssd), long and narrow leaflets (lnl), and early flowering (efl). The reduced plant height in Hyprosola apparently results from recessive mutation at two loci, rht-1 and rht-2, one of which is linked to ssd with 16 + 6% recombination. Desirable mutants for earliness, disease tolerance, the higher number of pods, and erect plant architecture were isolated from the second batch of irradiated Faridpur 1 seeds (Shaikh 1983). One mutant, G 299 proved its superiority over other mutants and Faridpur 1 (Shaikh et al. 1983). Sodium azide treatment of Hyprosola seeds resulted in the isolation of 15 true-breeding chickpea lines, 9 of which have more pods plant-1 and higher yield (Shaikh et al. 1985). These are undergoing further tests.
Mung Bean Simple correlation coefficients of some agronomic characters of 70 strains revealed a significant positive association of the number of pods and number of branches with yield plant-1 (Ahmed et al. 1981) Seed size, plant height, days to flowering, and maturity was negatively correlated with yield plant-1. Partial and multiple correlation coefficients also revealed a strong association of pods plant-1 with yield. It was concluded that pod plant-1 should serve as the best selection criterion for improving the yield potential of mung beans. Another study (Shamsuzzaman et al. 1983) showed that in addition to pods plant-1, the number of branches also was an important character for selecting high-yielding genotypes.
Two cycles of single plant selections of germplasm collected from Sitakundu (Ahmed et al. 1982) resulted in the isolation of a line, Accession no. MB 55, resistant to Cercospora leaf spot and tolerant of mung bean yellow mosaic virus ( MYMV). Its yield is 20% more than the recommended cultivar, Kishoregonj ( M B 63) (Tables 3 and 4) (Shaikh et al. 1988). Its seeds are about 25% larger than those of Kishoregonj (Ahmed et al. 1978).
Time-of-sowing experiments with 60 local and exotic germplasm lines through fortnightly sowings placed the accessions in groups like "real summer", "modified summer", and winter types. Some of these are of the short-duration type and fit well between two major crops (Begum et al. 1983). In multilocational trials, MB 146, a hybrid derivative from the cross of a mutant x V 5197 yielded more (Shaikh et al. 1988). An Asian Vegetable Research and Development Center ( AVRDC) entry V 2272 was comparatively free from YMV, and had more pods and more yield. Evaluation of gamma-ray-induced mutants and germplasm for disease incidence was carried out. Some of these breeding materials showed altered plant architecture and synchrony in maturity (Shaikh et al. 1985).
Black Gram: Number of pods and inflorescences plant-1 showed a high positive correlation with seed yield. Similarly, the former two characters were positively correlated with each other. Erect, disease-resistant, synchronous, early, and bold-seeded mutants were isolated following gamma-ray treatments (Shaikh and Majid 1982). Mutant M 23 is erect, synchronous, and determinate in growth habits. Its pods are hairless, bolder, clustered, and upright compared to horizontal/downward borne pods of the parental cultivars (Shaikh et al. 1982). Mutant M 25 is synchronous, determinate, slightly more dwarf and its pods are considerably less hairy than the parent B 10. In addition, M 25 is moderately resistant to CLS and YMV and is also higher-yielding than both B 10 and B 23 (Shaikh 1988).
Khesari Narrow ranges for days to maturity and number of seeds plant-1 were found by Shaikh et al. (1985). Variations for the number of pods plant-1, seed size, and yield plant - 1 were quite high. NaN3 treatment of Accession no. GP 1 resulted in the isolation of 32 mutants and 6 mutant families ( Ali et al. 1986). Mutants had different plant types, earliness, and flower colors. A number of pods plant-1 had the highest coefficient of variation and this character along with plant height were the main yield determinants. A negative corn-elation was found between seed size and neurotoxin p-(N)-oxalylamino-L-alanine (BOAA) content (Islam et al. 1986). Mutants and local germplasm lines were of the small-seeded type but had higher BOAA content. Exotic ones have a bigger seed size and lower BOAA content. Hybridization between the two groups was started with the objective of combining high yield and low neurotoxin content. Some lines with lower BOA A content and reasonably higher yields are under intensive yield testing.