Farmer participatory evaluation confirms higher grain yields in spring wheat using a selection index for spot blotch resistance, maturity and kernel weight

Abstract

Wheat (Triticum aestivum L.) cultivars for the warm regions of South Asia must produce high yields and possess resistance to spot blotch (Cochliobolus sativus), early maturity and high kernel weight. A study was conducted to determine the effectiveness of selecting for high grain yield based on a selection index for spot blotch resistance, maturity and kernel weight in four wheat crosses involving a susceptible cultivar and resistant genotypes. Initial selection of 40 progeny lines in each cross had been made using a selection index based on disease severity, days to heading and kernel weight as reported by Sharma and Duveiller [Crop Sci 43 (2003) 2031. The five highest grainyielding progeny lines from among the 40 lines in each cross, their parents and five popular commercial cultivars were evaluated in field trials at two sites in Nepal in the 2002 and 2003 wheat seasons. Multiple spot blotch assessments were made to determine the area under disease progress curve (AUDPC). Grain yield, thousandkernel weight (TKW), days to heading and plant height were examined. The wheat genotypes in the farmer's field were also ranked on the basis of cultivar preference criteria by the local farmers. The 20 progeny lines always showed a higher (+11 to +125%) grain yield and heavier (+10 to +44%) kernels than their parents and a lower (−83 to −89%) AUDPC than the susceptible parent. The progeny lines showed 98-100% grain yield, 97-100% TKW and 66-78% AUDPC compared to the highest grain-yielding commercial cultivar. Based on the farmers' preference criteria for a desirable wheat genotype, the best progeny lines ranked from 3rd to 5th, whereas the two commercial cultivars ranked 1st (Gautam) and 2nd (BL 1473). Results indicated that selection was effective in combining adaptation genes present in a local cultivar with some level of tolerance to spot blotch and resistance genes from exotic genotypes, which translated into improved agronomic performance and disease resistance. The selection index and farmer participatory approach used in this study could serve as a guideline in breeding efforts targeted for high yielding genotypes for wheat-growing conditions in South Asia where spot blotch is a serious biotic constraint to yield.

Genetic Improvement and Crop Management Strategies to Minimize Yield Losses in Warm Non‐traditional Wheat Growing Areas due to Spot Blotch Pathogen Cochliobolus sativus

“…being more promising. This approach was shown to be effective in the selection process to identify improved progenies (Sharma and Duveiller, 2003, 2006a). In many locations, screening for spot blotch in the field is based on natural infection at hot‐spot locations such as Bhairhawa and Rampur (Nepal), the Varanasi area in Uttar Pradesh (India) and the lowlands of Poza Rica (Veracruz) in Mexico.…”

Farmers' Perceptions on Rice Varieties in Sikasso Region of Mali and their Implications for Rice Breeding

“…They also found that PPB provided more information than non‐PPB at the same cost. Sharma and Duveiller (2006) reported that wheat variety selection based on the farmers’ preference criteria for desirable genotypes was effective in identifying varieties with superior agronomic performance and spot blotch disease resistance. In another successful case, Danial et al.…”

“…They also found that PPB provided more information than non-PPB at the same cost. Sharma and Duveiller (2006) reported that wheat variety selection based on the farmers' preference criteria for desirable genotypes was effective in identifying varieties with superior agronomic performance and spot blotch disease resistance. In another successful case, Danial et al (2007) reported that breeders learnt about male and female farmers' selection criteria of preferred varieties and used the knowledge in the selection and development of new wheat, barley, common bean, quinoa, potato and maize cultivars in the Andean region.…”

Participatory wheat varietal selection in Gilgit Baltistan of Pakistan

“…However, green revolution has not improved wheat production in marginal areas of the world having resource poor farmers (Sthapit et al, 1996). In order to address the problems of resource poor farmers, farmer participatory approaches were advocated by many workers (Farrington and Martin, 1988;Sthapit et al, 1994;Josi and Witcombe, 1996; Witcombe, 1996;Witcombe et al, 2003;Weltzien et al, 2003;Ashby and Lilja, 2004;Morris and Bellon, 2004;Ceccarelli and Grando, 2005;Mangione et al, 2006;Sharma and Duveiller, 2006) in selection and breeding programs. In centralized breeding system, a number of advanced breeding lines are tested and selected under research station conditions that may not resemble the environmental conditions where the lines will be subsequently grown.…”