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Pearl millet [Pennisetum glaucum (L.) R. Br.] is grown widely in the arid and semi-arid tropical regions in Indian subcontinent and African continent under the most adverse agro-climatic conditions where other crops like sorghum and maize fail to produce economic yields. Its grains are valued as human food while its dry stover makes important livestock ration in crop-livestock farming system. Enormous progress has been made in the genetic improvement of pearl millet in India during last several decades. This paper presents an overview of strategies followed in genetic improvement of pearl millet, assesses the impact of this research on crop productivity and presents its future prospects in climate-change scenario for providing food and nutritional security. The genetic improvement programme evolved strongly starting from selection in local and traditional material and reaching development of high-yielding hybrids with in-built resistance to diseases and tolerance to climatic stresses like drought and heat. The major approach in hybrid breeding has been to strategically utilize germplasm from Africa and Indian subcontinent with the result that a large number of genetically diverse hybrids have been developed with different combinations of phenotypic traits that are important for adaptation to different ecological regions. The genetic diversification of hybrids has proved very critical to contain downy mildew epidemics which had threatened hybrid technology per se in mid-1970s. A great deal of work has been done on understanding the epidemiology of different diseases and crop response to moisture stress that helped in developing diseaseresistant and stress-tolerant cultivars. More than 100 cultivars with a combination of diverse phenotypic traits have been released in the last 25 years, providing a wide range of choice to farmers in different production ecologies of the crop. These cultivars have been widely adopted by Indian farmers with the result that the crop productivity has gone up from 305 kg ha-1 during 1951-1955 to 998 kg ha-1 during 2008-2012, registering a 227 % improvement which assumes greater significance given that more than 90 % of pearl millet is grown as rainfed and often on marginal lands. In future, pearl millet is likely to play a greater role in providing food and nutritional security. Pearl millet would also be an excellent genomic resource for isolation of candidate genes responsible for tolerance to climatic and edaphic stresses for accelerating further genetic improvement of this crop as well as for their possible deployment in the genetic improvement of other crops.

Journal articleIFPRI3; ISIEPTDP

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A methodology for probabilistic modeling of fatigue damage accumulation for single stress level and multistress level loading is proposed in this paper. The methodology uses linear damage accumulation model of Palmgren-Miner, a probabilistic S-N curve, and an approach for a one-to-one transformation of probability density functions to achieve the objective. The damage accumulation is modeled as a nonstationary process as both the expected damage accumulation and its variability change with time. The proposed methodology is then used for reliability prediction under single stress level and multistress level loading, utilizing dynamic statistical model of cumulative fatigue damage. The reliability prediction under both types of loading is demonstrated with examples.

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