Evaluation of Central Asian wheat germplasm for stripe rust resistance

Abstract

Stripe rust, caused by Puccinia striiformis f.sp. tritici (Pst), is an important disease of winter wheat in Central Asia. Stripe rust races contain diverse virulence/avirulence patterns and change rapidly. Therefore the objectives of this research were to: (i) examine current pathotype variability of Pst races collected from Kazakhstan and Uzbekistan and (ii) evaluate stripe rust resistance in leading cultivars and advanced breeding lines targeted to those regions. Analyses of 152 Pst samples showed diverse virulence patterns with avirulence to Yr5, Yr10 and Yr15 being common. Most of identified races are among the rare. Analysis of a mixed Pst population showed 10 distinct pathotypes with frequencies ranged from 1.2 to 8.7%. The virulence patterns ranged from least ‘31–1.5’ and X-1.5 to highly virulent ‘86 + E16’. Seedling evaluation of 62 genotypes using the 10 pathotypes showed variations for resistance. Bunyodkor and Barhayot showed resistance to all pathotypes. Five Yr genes were postulated. Yr1 in KR12-5075, and Yr6 in KR11-03 and KR12-5003 were postulated. Yr5 combined with Yr10 and Yr15 genes were determined in Bunyodkor. The wheat genotypes also showed different levels of resistance in adult plant stage under field conditions. Twenty genotypes showed <20% severity in both Kazakhstan and Uzbekistan. The disease severity on several genotypes differed in this countries, suggesting different Pst populations in the two countries. Several resistant genotypes were identified, which should be further evaluated for release as new varieties or used in breeding programmes. Two resistant lines from this study were identified as new varieties in Georgia and Uzbekistan.

Pyrenophora tritici-repentis population structure in the Republic of Kazakhstan and identification of wheat germplasm resistant to tan spot

“…One of the main reasons for the reduction in yield of wheat in Kazakhstan are the diseases with airborne infection. Dominant position as a part of the pathogenic complex of wheat in the south and south-east of Kazakhstan took rusts (yellow, stem and leaf rust) (Kokhmetova et al, 2011(Kokhmetova et al, , 2016b(Kokhmetova et al, , 2018bRsaliyev A.S., Rsaliyev Sh.S., 2018), as well as leaf spot di seases (tan spot and Septoria) (Kokhmetova et al, 2017(Kokhmetova et al, , 2018a(Kokhmetova et al, , 2019.…”

Genetic Variability of Perspective Btreeding Material of Spring Bread Wheat for Resistance to Leaf Rust in Russia and Kazakhstan

“…Winter wheat cultivars are grown in the southern regions of the country, and spring wheats -in the Northern, Western and Eastern regions. Developing high yielding and leaf rust, stripe rust and stem rust resistant cultivars is an important objective of winter and spring wheat (Triticum aestivum L.) improvement programs in Central and West Asia [4][5][6][7][8]. Production of wheat in Kazakhstan is being constrained also by leaf spotting diseases, including tan spot, caused by Pyrenophora tritici-repentis [9][10][11][12][13] and common bunt, caused by Tiletia caries [14].…”

Evaluation of Wheat Germplasm for Resistance to Leaf Rust (Puccinia triticina) and Identification of the Sources of Lr Resistance Genes Using Molecular Markers

“…Wheat-growing regions of Kazakhstan have been facing frequent occurrences of leaf rust epidemics. Between 2001 and 2009, North Kazakhstan suffered leaf rust epidemics that occurred five times (2002, 2003, 2005, 2007, and 2009), and the yield loss due to leaf rust has been reported to range from 10% to 50% in the most susceptible cultivars [ 3 , 14 ]. Leaf rust in Kazakhstan is spread from 4% to 61% of the surveyed area, which represents approximately from 0.5 to 3 million hectares.…”