Farm Level Genetic Diversity in Pearl Millet in India M C S Bantilan, U K Deb, S D Singh International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Patancheru 502 324, Andhra Pradesh, India

Introduction  Pearl millet — suitable crop adapted for marginal environments   characterized by high risk, erratic rainfall and low soil fertility.  Ensuring stability in pearl millet production is important for food   security.  Diversity in pearl millet cultivars grown is required to ensure long-  term stability in yield. Objectives  Identify composition of materials grown in farmers’ fields.  Quantify extent of genetic diversity in farmers’ fields.  Impact of improved cultivars on genetic diversity.  Draw implications on research strategy to ensure long term   stability via increased genetic diversity. Research Methods  Surveyed 360 farmers from 36 villages in 18 blocks spread over   9 districts of Maharashtra (India) for the period 1990-99  Gathered information about the cultivars grown and extent of   cultivation  Traced parentage of cultivars grown by the farmers  Computed Diversity Index D using Herfindahl Index (H)  H = S ((Share of cultivar))2   D = 1 – H   Larger the value of D, higher the level of diversity  Computed Coefficient of Genetic Diversity (COD)   using Souza et al. (1994)   COD = 1 – COP   where, COP is coefficient of parentage. Each cultivar has a COP with itself of 1, and each pair of cultivars without any common parentage has COP = 0, with unrelated parents the COP between parent and offspring is 0.5.The higher the COD value the greater the genetic diversity.  Average Diversity (Da) = 1 – GiPGi’   where, Gi is a row vector of weighting values, Gi’ its transpose. Any cultivar grown in a region in year i receives a weight of n-1 (where n is the number of cultivars grown in that year), and other cultivars receives a weight of 0.  Weighted Diversity (Dw) = 1 – AiPAi’   where, Ai is the vector of the proportion of the area sown to each cultivar in year i, and Ai’ its transpose. Major Downy Mildew Epidemics in India 1971 to 1977 : 25-35% production loss 1981             : 20% production loss 1986             : 15% production loss Downy Mildew Resistant Cultivars BJ 104 was resistant up to 1971 WC-C75 released in 1982 ICTP 8203 is released in 1988 ICTP 8203 replace MBH 110, ICMH 169, and ICMH 179 Improved Cultivars Grown by Farmers ICRISAT bred WC-C75, ICTP8203, MH-179 Public (ICRISAT material) MH-169, RHRBH-8609 Private (ICRISAT material) MLBH 104, MLBH 267, GK 1004, EKNATH, VIJAY-4, JK-26 Public BK-560, RHRBH-8924 Private PIONEER, PROAGRO, MAHYCO 163, MBH 110, PLANTGENE, PARAS, KANCHAN PRATAP

Trends in Adoption of Improved Cultivars  Rate of adoption of improved cultivars has increased over   time.  Area under ICRISAT bred cultivars are decreasing due to new   releases from other sources.  Public research institutes releases based on ICRISAT   materials has substantially increased in 1999, compared to   1990.  Private sector releases are increasing.  Local cultivars are still grown in some villages (eg. Sangli,   Satara) to a significant extent due to good fodder quality and   quantity and better taste of grain. Percentage share of different cultivars