Evaluating natural infection of fungal, bacterial and viral pathogens to dry bean genotypes under field conditions

Abstract

Fungal, bacterial and viral diseases are economic foliar diseases that cause yield losses, between 40 and 100%, in commonly grown dry bean cultivars in the world. Development of disease resistance genotypes is a complex interaction between genetic and environmental factors. This study focused on determining the natural infection of disease-causing pathogens of angular leaf spot, powdery mildew, bacterial blight and bean common mosaic virus in different agro-ecologies in relation to grain yield. Diversity of 211 bean genotypes were tested at two different disease hot spots areas under incomplete block design, with two replications for two cropping seasons in Tanzania. Diseases severity was significantly different (p<0.001) for genotypes and their interactions with the environment and season. Higher disease severity was observed at Lyamungo site than Selian site. Effects of genotypes by environment were observed with maximum yield of 2170 kg/ha to low yield of 398 kg/ha with the grand mean of 1151.54 kg/ha. High annual rainfall and relative humidity contributed to disease development among the tested environment. Five genotypes (FEB 189, A774, NUA 16, KG 71-4 and DOR 766) expressed trait of resistance to above diseases and are advised to be incorporated in breeding programs for enhancing dry bean productivity.

Genome-wide Identification of Powdery Mildew Resistance in Common Bean

“…The environment was used to fully assess the PM resistance potentials of common bean genotypes in nature. As a result, highly signi cant (p<0.001) differences of resistant trait were observed among the 211 genotypes for powdery mildew in both 2017 and 2018 growing season [27]. Also, high signi cant interactions of genotype x environment (location and year) were observed, indicating the resistance to PM disease is affected by environments (Table 1).…”

“…Phenotyping for powdery mildew disease Two trial sites were ideal experimental locations for testing PM disease resistant trait because of their higher disease pressure due to consecutively growth bean for more than ve years resulting in the accumulation of E. polygoni inoculum season after season. The higher rainfall (>1000 mm) and higher relative humidity (>80%) also created conducive environment for disease development during these two bean growing seasons [27]. The environment was used to fully assess the PM resistance potentials of common bean genotypes in nature.…”

“…Seeds of 206 common bean lines were originally sourced from different germplasm centers [27]. Among them, 179 genotypes seeds were originally acquired from the common bean germplasm repository at International Center for Tropical Agriculture (CIAT) (www.ciat.cgiar.org) and the remaining 27 were derived from Tanzania Agricultural Research Institute (TARI) Selian center where they were originally collected from Ethiopia (12), Kenya 10…”

Genome-wide Identification of Powdery Mildew Resistance in Common Bean

“…Phenotyping for powdery mildew disease Two trial sites were ideal experimental environmentsfor testing PM disease resistant trait because of their higher disease pressure due to consecutively growth bean for more than ve years resulting in the accumulation of E. polygoni inoculum season after season. The higher rainfall (>1000 mm) and higher relative humidity (>80%) also created conducive environment for disease development during these two bean growing seasons [28]. The environment was used to fully assess the PM resistance potentials of common bean genotypes in nature.…”

Genome-Wide Association Study of Multi-Traits in Common Bean (Phaseolus Vulgaris L.)

“…A natural population of 206 common bean genotypes collected from International Centre for Tropical Agriculture, CIAT -Uganda (179), Ethiopia (12), Kenya (10), Tanzania (3) and Rwanda (2) were used in this study [49]. The experimental materials were planted in the northern Tanzania at medium altitudes with 1407 m above sea level (a.s.l) of S03 21.690' and E36 37.879' (Selian Agricultural Research Institute, abbreviated SARI) and at low altitudes with 992 m a.s.l of S03 19.905'and E037 14.067' (Tanzania Coffee Research Institute, commonly called Lyamungo) in 2017 and 2018.…”