Evaluation of tomato germplasm adaptable to abiotic stress conditions of Northern India

Over large areas, tomato production in India is being adversely affected by less favourable environmental conditions (abiotic factors) such as low and high temperature, drought, flooding and soil salinity. The National Bureau of Plant Genetic Resources (NBPGR), over the years, has assembled ca 2900 germplasm lines from diverse agro-elimatic zones of the world (over 45 countries) and from within India. This includes several wild species viz., Lycopersicon pimpinellifolium, L. hirsutum, L. cheesmanii, L. peruvianum, L. glandulosum, L. chilense, L. chmieliwskii, L. parviflorum, L esculentum var. cerasiforme. L. hirsutum f glabratum, L. peruvianum var. humifusum. Development of resistant cultivars against abiotic factors is an economical proposition. Realising possibilities of use of stress resistance, the germplasm were tested/evaluated under field Collations during hot summers (April-June) in Delhi (max. temp. 40°-44°C) and attempts were made to identify germplasm pertaining to definite sources of resistance i.e., ability for tolerance to temperature stress, drought conditions and reaction to diseases and pests, to develop lines possessing resistance to stress and other propositions. Evaluation studies (at Delhi when temperature is about 38°-40°C) revealed that 46 accessions are heat tolerant/moderately heat tolerant induding the wild species, 21 of processing types, 12 accessions suitable for transportation and 29 and 56 accessions are resistant/tolerant to diseases and fruit borer, respectively. Forty accessions were scored for high yielding potentiality. L. pimpinellifolium required more number of days for expressing wilting, thus showing tolerance to drought conditions. Wild species L. esculentum var. cerasiforme-tolerant to stress, L. hirsutum-tolerant to drought) possess resistance to abiotic factors.