Isozymes variability among Fusarium udum resistant cultivars of pigeonpea (Cajanus cajan (L.) (Millsp)

Abstract

The present study was carried out to select the different pigeonpea cultivars for resistance against wilt caused by Fusarium udum and to assess the genetic variability among the resistant and susceptible cultivars. These cultivars were screened by root dip inoculation and classified into resistant (ICP 8863 and 9145), moderately resistant (ICP 11681 and Selection-1), susceptible (ICP 7118, TRG-1 and LRG-30) and highly susceptible cultivars (1CP-2376 and LRG-41). The peroxidase activity (PEO) in both leaf and root tissues of four pigeonpea cultivars (ICP 8863, Selection-l, ICP 2376 and LRG-30) were determined at 1 st, 4 th and 7 th day after inoculation (DAI) in healthy and F. udum infected tissues. Hitcher PEO activity in both leaf and root was observed and at 4 DAI in susceptible cultivars. In native-PAGE analysis of isozymes, the induction of specific leaf peroxidase band (Em = 0.17) and two root peroxidase bands (Em = 0.24 and 0.55) were observed in ICP 8863 after inoculation. Significant differences were observed in the leaf phosphatase and esterase banding profiles of all the cultivars. The presence of leaf phosphatase band at Em of 0.04 was observed only in ICP 8863 and 11681. The leaf esterase band (Em = 0.3) was well expressed in ICP 8863 when compared to other cultivars. The significance of peroxidase in plant defense mechanism and utility of biochemical markers in breeding programmes are discussed.

Genetic Diversity Studies and Identification of Molecular and Biochemical Markers Associated with Fusarium Wilt Resistance in Cultivated Faba Bean (Vicia faba)

“…Several studies have investigated alterations in isozyme patterns in plants infected with different pathogens. Prasad et al (2003) analyzed isozyme variability among Fusarium udum resistant cultivars of pigeon pea (Cajanus cajan L.). They concluded that the polymorphisms observed among isozymes such as peroxidases, phosphatases and esterases may be helpful in the characterization of resistance and susceptibility.…”

“…Isozymes, peroxidase, polyphenol oxidase, superoxide dismutase, and pathogenesis-related proteins, such as chitinase and β-1,3-glucanase, have very important roles in resistance to plant pathogenic fungi (Prasad et al, 2003). Natural resistance is genetically controlled, and resistance genes are expressed through the production of biological products such as secondary metabolites, including phenolics, lignin, suberin, phytoalexins, alkaloids, terpenes, glycosides, degrading enzymes, and pathogenesis-related proteins, all of which contribute to disease resistance (Gupta et al, 2010).…”

The first set of EST resource for gene discovery and marker development in pigeonpea (Cajanus cajanL.)

“…Fusarium wilt (FW) caused by Fusarium udum is an important biotic constraint in pigeonpea production in the Indian subcontinent, which results in 16-47% crop losses [ 5 ]. The fungus enters the host vascular system at the root tips through wounds or invasion made by nematodes, leading to progressive chlorosis of leaves, branches, wilting and collapse of the root system [ 6 ].…”

Inheritance studies on Fusarium wilt resistance in long duration pigeonpea [Cajanus cajan (L.) Millsp.]

“…Yield losses of wilt susceptible crops ranged from 16 to 47% (Prasad et al, 2003) or even 100% (Reddy et al, 1990) causing losses up to 71 million US $ annually in India alone (Reddy et al, 1993). Wilt symptoms usually appear during flowering and pod stage of the crop.…”