Breeding for rainfed lowland, deepwater,and boro land in Bihar, India, achievements and challenges

Rice in Bihar covers about 3.8-3.9 million ha of land under diverse ecological conditions. More than 70% of this area is rainfed. The rainfed lowland is the most important ecological system followed by deep water. The state has two geographical divisions, north and south, and in both divisions rice is the main crop. Because of the wide diversity in Riceland in Bihar, productivity is poor. However, in recent times and in collaboration with IRRI, there has been significant progress in developing improved varieties for different situations, with the breeding program being reoriented on the basis of existing challenges and needs. Rainfed lowlands in Bihar fall within two broad categories favorable and favorable the favorable ecosystem virtually resembles the irrigated system, whereas the unfavorable ecosystem is highly variable.Varietal requirements for these two ecosystems are different, consequently selection and evaluation criteria are modified. New entries are now evaluated jointly by farmers and scientists using farmers' management practices. Through this process, a pureline selection, Vaidehi, was developed, while two other high-yielding varieties, Satyam and Kishori, were ere bred under the shuttle breeding program. Both have multiple resistance to biotic and abiotic stresses and are adapted to late planting. Santosh, a variety with good grain quality,was developed throught he farmers participatory breeding project.In deepwater ice land,excess water causes serious damage and more tolerant and higher yielding varieties are needed.Boro (dry-season) rice,grown from Oct.-Novt.o Apr.-May, is highly productive, but germplasm with tolerance for cold stress at the seedling stage is required to expand the boro area. Recently, an EMS mutant genotype,Rasi,was developed with high cold tolerance and high yield potential( moret han 8 t ha-1). It was released as Gautam.In subsequent years, Richharia, Dhanlaxmi, and Saroj( all with different maturity durations) were developed for the boro season. These varieties are becoming more popular and cultivated area is progressively expanding in traditional and nontraditional boro regions. There is now a subtle change in the attitude of farmers, yield is no longer the sole criterion for adopting new varieties, they also assess other traits such as cooking quality and an attractive look. This shift in preference could help popularize new varieties with good grain quality,even in the rainfed ecosystem.