An assessment of diversity pattern and genetic relationships of the response of rice varieties to stresses

Abstract

Multiple stress management is a major solution to high yield reduction experienced in farmers’ fields.  Studies were conducted to assess the variability of response of four major pests of rice to a total of one hundred and nine rice varieties.  These constraints include blast.  African rice gall midge, iron toxicity and drought.  African rice gall midge and iron toxicity studies were conducted at Edozhigi (Central Nigeria) in a natural field condition.  Blast studies were conducted at International Institute of Tropical Agriculture under artificial inoculation while drought was screened at Badeggi (Central Nigeria) in dry days.  The result showed that the diversity of the test materials to the stresses varies with respect to the dates scoring as well as from year to year.  Mean values for all the stresses showed that none of the test materials possess resistant genes to the four stresses.  Blast scores showed more diverse gene distribution from moderately susceptible to highly susceptible levels than the other stresses.  The computer drawn dendogram produced thirteen groups at 100% level of similarity.