Characterisation of Phaseolus coccineus interspecific germplasm accessions for disease resistance, grain market class and yield attributes

Sister species of the common bean ( Phaseolus vulgaris L.) are an attractive genetic resource to broaden the genetic base of this crop, especially for adaptation to extreme environments. The runner bean (Phaseolus coccineus) in particular, has been shown to contribute to disease resistance and tolerance to low soil fertility, and has been used to introduce these traits into the common bean. The objective of this study was to identify germplasm with agronomic traits suitable for cultivation from an interspecific population (Phaseolus coccineus G35346 x P. vulgaris; SER 16) of 186 bush lines. The lines, coded ALB and one yield check, CAL96, were field evaluated for three rain seasons; 2011a (March-June), 2011b (September-November) and 2012 (March-June) at the National Agricultural Research Laboratories (NARL)-Kawanda, Uganda. Artificial inoculum of bean common mosaic virus (BCMV) was applied to the field experiment in 2011a. The morphological (seed type and growth habit) and agronomic attributes (plant vigour, days to physiological maturity; DPM and days to 50% flowering; DF), reaction to occurring diseases and yield performance were monitored. The lines including root rot resistant and susceptible checks; MLB-49-89A, RWR 719 and CAL 96, were also subjected to inoculum of two major root rot pathogens; Fusarium solani f.sp. phaseoli (isolate FSP3) and Pythium ultimum (isolate MS61) under screen house conditions to select for root rot resistance. Results indicated significant differences (P