Genetic variation of blast (<i>Pyricularia oryzae</i> Cavara) resistance in rice (<i>Oryza sativa</i> L.) accessions widely used in Kenya

Abstract

A total of 47 rice accessions collected from Kenya were investigated the genetic variations and classified into two cluster groups, A and B, by polymorphism data of 65 simple sequence repeat (SSR) markers. Clusters A and B corresponded to Japonica and Indica Groups, respectively. The number of Japonica Group accessions was limited in comparison with those of the Indica Group. Based on their patterns of reaction to standard differential blast isolates (SDBIs), these accessions and 57 control cultivars including differential varieties and several accessions harboring partial resistance genes were classified again into three cluster groups: Ia (high resistance), Ib (intermediate resistance) and II (susceptible). The rice accessions from Kenya were classified only into groups Ia and Ib. The accessions from Kenya were finally classified into three categories, A-Ia, B-Ia and BIb , based on the two classifications of polymorphism of SSR markers and resistance. The Indica Group accessions had wider genetic variation for blast resistance than did the Japonica Group accessions. The three leading cultivars (Basmati 217, Basmati 370 and ITA 310) categorized into Cluster group Ia were susceptible to some SDBIs from Kenya. The genetic variation for blast resistance in Kenya was demonstrated as the first report using SDBIs.

Soil and plant health in relation to dynamic sustainment of Eh and pH homeostasis: A review

“…A second hypothesis can also be proposed that, besides the specific recognition processes depending on host and plant pathogen genotypes, varietal resistance, tolerance and susceptibility to pests is related to differences in basal Eh-pH and genetic capacity of the variety to sustain a balanced Eh-pH. For instance, the rice variety Nerica 4 sustains a low Eh and pH and is resistant to several strains of the rice blast pathogen while the more oxidized rice variety IRBLTA-2Pi was highly susceptible to some strains of the pathogen (Fukuta et al 2019). Similarly, greater varietal resistance of wheat to the blast pathogen was related to a more efficient antioxidative system in the removal of excess ROS generated during the infection process of M. oryzae, limiting cellular damage caused by the fungus (Debona et al 2012).…”

Panicle blast severity identification in advance generation rice lines

“…Various studies for blast had been generated [7,8,17,[9][10][11][12][13][14][15][16]. Establishing a new resistant variety would be more effective if the selection was conducted at the endemic areas because blast infection depends on a specific environmental condition.…”

Genetic variation of rice (<i>Oryza sativa</i> L.) germplasm in Cambodia

“…Following those Japanese studies, several genetic analysis studies using the same set of SSR markers were conducted to clar-ify genetic variations of rice germplasm in other parts of Asia and in Africa. Wunna et al (2016) investigated 175 accessions from Myanmar; Khan et al (2017) Fukuta et al (2019) investigated 47 accessions in Kenya; and Muto et al (2019) investigated 314 accessions in Laos. Thus, SSR markers are a useful tool for the clarification of genetic variations and for differentiation among AA genome species and between Indica Group and Japonica Group cultivars, between lowland and upland cultivars, and between landrace and improved types in rice.…”

“… Wunna et al (2016) investigated 175 accessions from Myanmar; Khan et al (2017) investigated 334 Bangladeshi rice accessions; Odjo et al (2017) investigated 195 accessions comprising three species of the AA genome complex (Asian rice [ O. sativa L.], African rice [ O. glaberrima Steud. ], and wild rice [ O. barthii ]); Fukuta et al (2019) investigated 47 accessions in Kenya; and Muto et al (2019) investigated 314 accessions in Laos. Thus, SSR markers are a useful tool for the clarification of genetic variations and for differentiation among AA genome species and between Indica Group and Japonica Group cultivars, between lowland and upland cultivars, and between landrace and improved types in rice.…”

“…Several studies followed, clarifying the genetic variations for blast resistance in rice germplasm based on inoculation tests using SDBIs. Kawasaki-Tanaka and Fukuta (2014) found a wide variation of blast resistance in 324 Japanese rice accessions, including landrace, improved, and weedy types, using 16 SDBIs from Japan and the Philippines; Odjo et al (2017) studied blast resistance in 195 accessions comprising three species of the AA genome complex, based on 32 SDBIs from Japan and West Africa; Khan et al (2017) studied blast resistance in 334 Bangladesh accessions from four major ecotypes (Aus, Aman, Boro, and Jhum) using 20 SDBIs collected from Bangladesh, Japan, and Kenya; and Fukuta et al (2019) studied blast resistance in 47 Kenyan accessions using 15 SDBIs from Japan, the Philippines, and Kenya. Thus, the genetic variation of resistance in rice germplasm has been clarified based on the reaction patterns to SDBIs.…”