Solar UV-B and UV-A/B exclusion effects on intraspecific variations in crop growth and yield of wheat varieties

Abstract

UV exclusion studies would help in the assessment of the sensitivity of varieties to ambient level of UV radiation. A field study was conducted to determine the intraspecific responses in relative to sensitivity of Indian wheat ( Triticum aestivum L.) varieties to ambient solar ultraviolet (290–400 nm) radiation. Specifically, the influence of ambient UV radiation on crop growth and yield parameters was investigated by the exclusion of UV radiation form solar spectrum using four Indian wheat varieties; Naveen Chandausi, Swarna, Vidisha and Purna. The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded both UV-A/B (<400 nm), UV-B (<315 nm), transmitted all the UV (280–400 nm) or lacked filters. Exclusion of UV significantly enhanced plant height, tiller number, flag-leaf area, dry matter accumulation and yield parameters like number of grains and grain yield in all the four wheat varieties tested. Purna and Vidisha showed more enhancements compared to Swarna and Naveen Chandausi. Sensitivity index showed that all four varieties were UV-sensitive; SI was higher for N. Chandausi and lowest for Purna and it was in the following sequence; Naveen Chandausi > Swarna > Vidisha > Purna. Thus Purna was the most sensitive and Naveen Chandausi the least sensitive to current level of solar UV radiation. The intraspecific differences in sensitivity identified among the wheat varieties imply the options for selecting varieties with increased tolerance to UV-B/UV-A radiations to future attempts in plant breeding.