Disease Incidence and Genetic Analysis of Adult Plant Resistance to Leaf Rust in Some Egyptian Wheat Cultivars

Abstract

This research has been carried out to study the disease incidence and genetic analysis of adult plant resistance to leaf rust in eight Egyptian wheat varieties, Misr1, Misr2, Misr3, Gemmeiza11, Gemmeiza12, Sids1, Shandweel-1 and Sakha94 crossed with Triticum spelta saharensis (T.s.s.) as a highly susceptible tester wheat variety at Bahtem Agricultural Research Station, Agr. Res. Center during 2018-2021 growing seasons. The nine wheat genotypes and F2 plants of eight crosses with T.s.s. were estimated to disease incidence measurements and quantitative genetic analysis to leaf rust adult plant resistance. The nine wheat genotypes tested were divided into two resistance groups according to disease incidence measurements (FRS, r-value and AUDPC), the first group having the high and moderate levels of partial resistance i.e., Misr1, Misr2, Misr3, Gemmeiza12, Shandweel-1 and Sakha94, this group is of major importance for efficacious breeding for leaf rust durable resistance, while cultivars Gemmeiza11, Sids1 and T.s.s. were included in the second group with high values of FRS, r-value and AUDPC. The F2 populations, F1 and parents for each of the eight crosses were tested for adult plant disease severity. The quantitative analysis of the F1and F2 mean value of leaf rust severity in the eight crosses was mostly lower than the mean value estimated for their respective mid parents and indicated that rust resistance was partial dominance expecting crosses (T.s.s. × Sids1) in F1 and (T.s.s. × Gemmeiza11) in F2, the positive values were higher than the respective mid-parents, which indicates existence an over-dominance towards susceptibility of these crosses. The heritability in its broadsense estimated from the variance parents F1and F2 for partial leaf rust resistance, is considered to be high in magnitude, since the values ranged from 63.99 to 96.51%. The number of genes of each analyzed parent is controlled by three, two and a pair of genes. Generality, this outcome in the adult plant stage suggests which selection for this trait may be possible in the first segregating generations. Although the delay would be more efficacious, according to the important role that dominance impacts play in trait expression the selection of resistant adult plants in the subsequent generation of segregation would be useful for the development of a high-yielding wheat genotype under Egyptian condition.

Detection and Introgression of Lr46 Gene-Conferring Partial Resistance to Leaf Rust (Puccinia triticina) in Wheat

“…This supporting the hypothesis of one another dominant gene rules the resistance to leaf rust disease in this cross. These results agree with EL-Orabey et al (2020) and Mabrouk et al (2021).…”

“…These high estimates also suggest that selection for this feature may be achievable during the initial generations of segregation. Given how crucial dominant impacts are to the evolution of this trait, a delay would be more effective (Abd El-Latif and Boulot, 2000;Menshawy and Youssef, 2004;Da-Silva et al, 2012;Loladze et al, 2014;Hermas and El-Sawi, 2015;EL-Orabey et al, 2020 andMabrouk, et al, 2021).…”

Determining the impact of stripe rust and leaf rust on grain yield and yield components' losses in Indian wheat cultivars

“…Yield component losses were the least in this group compared to other groups with different adult plant resistance and susceptible 'S' reaction. Similar results were described by various workers (Hailu and Fininsa 2009;Herrera-Foessel et al 2006;Safavi 2015;Mabrouk et al 2021;Dinglasan et al 2022) as they reported that the resistant cultivars have the least losses in yield components under high disease pressure. Although, cultivars in this group have resistant reaction with no pustulation, however, they showed minimum losses under high disease pressure.…”

How to Differentiate between Resistant and Susceptible Wheat Cultivars for Leaf Rust Fungi Using Antioxidant Enzymes and Histological and Molecular Studies?

“…These findings generally conflict with those recorded by Abdelbacki et al [30], who discovered that the cultivars Gemmeiza-11, Sakha-94, Sakha-95, Giza-168, Giza-171, Sids-12, Sids-13, Misr-1, and Misr-2 were resistant to leaf rust during the 2011/2012 and 2012/2013 growing seasons or had only moderate resistance. Moreover, Mabrouk [31] demonstrated that during the growing seasons of 2013-2016, the Gemmeiza-9, Gemmeiza-10, and Gemmeiza-11 wheat cultivars had FRS% ranging from 23.33 to 50% in four locations. These findings could result from the existence of new races in Puccinia triticina populations that can disrupt the resistance genes in these cultivars [32].…”