Exploration, Collection and Characterization of Horsegram [Macrotyloma uniflorum (Lam.) Verd.] Germplasm

Background: Horsegram [Macrotyloma uniflorum (Lam.) verd.] is an underutilized arid food legume known to grow well in diverse environmental conditions like poor soils, low rainfall etc. Horsegram is a drought resistant crop used for fodder, feed, seed, green manuring and in ayurvedic medicine. It is grown as Rabi crop in Andhra Pradesh. Compared to other pulse crops, efforts in conservation horsegram germplasm is poor which is essential for the future breeding purpose. There will be a danger of loss of germplasm if they are not collected and conserved. The Eastern Ghats of Andhra Pradesh i.e., Araku region is a rich source of diversified germplasm of legumes, medicinal plants, millets and ancient crops. Among which, horsegram is one of the crop with wide diversified germplasm. Hence the present effort is done in collection and characterization of the germplasm for further use in the breeding process. Broadening the genetic base in horsegram through interspecific hybridization employing diverse germplasm will be useful in improving pest and disease resistance, grain quality, protein percentage and nutritional factors.  
Methods: Expedition was conducted during Rabi 2018 and 25 horse gram seed samples were collected from the local regions of tribal tracts of Eastern Ghats of Andhra Pradesh along with passport data using the GPS machine. The germplasm lines were evaluated and morphologically characterized during Rabi 2019 at Agricultural Research Station, Yellamanchili, Visakhapatnam, Andhra Pradesh, India, for fifteen characters. Principal component analysis was carried out to identify the diverse germplasm lines and to know the contribution of the variables. 
Result: The investigation showed that all the horse germplasm lines are inherited to the farmers from their ancestors. Study revealed that, the seed yield per plant showed a range of 2.40 to 6.40 g and the days maturity recorded a range of 87 to 106 days. Principal component analysis showed that all the variables except 100 seed weight (g) showed positive loading. Among the variables plant height (cm), dry haulm weight (g) and seed yield per plant recorded maximum percentage of contribution. The genotypes HG-24, HG-7, HG-19, HG-15, HG-22 recorded highest positive scores. The genotypes HG-5, HG-10, HG-3, HG-16, HG-8, HG-4, HG-10, HG-24 and HG-7 has shown wide divergence which may be further adopted in the breeding programme for horsegram improvement.