Association between molecular markers and blast resistance in an advanced backcross population of rice

Abstract

An advanced backcross population consisting of 80 BC(3)F(3) lines derived from rice vars. Vandana/ Moroberekan was analysed for blast resistance and genotyped with 50 candidate genes and 23 simple sequence repeat (SSR) markers. Six candidate defence response genes [thaumatin, three nucleotide-binding site-leucine-rich repeat sequences from maize and two resistance gene analogue (RGA) markers] and one SSR marker (RM21) were significantly associated with partial blast resistance in rice ( P=0.01). These markers accounted for phenotypic variation ranging from 9.6% to 29.4% and contributed to 76% of the total variation of percentage diseased leaf area (DLA) observed under natural infection. Four candidate genes (oxalate oxidase, 14-3-3 protein and two RGA markers) and four SSR markers (RM21, RM168, RM215 and RM250) were significantly associated with resistance to a single pathogen isolate, PO6-6. Among these, two markers were for DLA, five for lesion number and one for lesion size. These markers accounted for 9.1-28.7% of the phenotypic variation. A moderate correlation ( r=0.48, P<0.01) was found between the level of partial resistance measured in the greenhouse and that measured under natural conditions. Analysis of BC(3)F(4) progeny using genotypes of BC(3)F(3) confirmed the phenotypic contribution of these markers. Cluster analysis of DNA profiles showed that the BC(3) population was genetically similar (>85%) to the recurrent parent Vandana. Although no obvious relationship between DNA profiles and resistant phenotypes was observed, three lines (VM19, VM46 and VM76) in a cluster with high similarity to Vandana (89-96%) expressed a high level of partial blast resistance in the field. Analysis of disease progress in the field confirmed the performance of selected lines based on greenhouse and nursery analyses. The advanced backcross progeny with resistance phenotypes tagged by markers will be useful for accumulating blast resistance in upland rice.

Microspore embryogenesis in barley: anther pre-treatment stimulates plant defence gene expression

“…These genes are known to respond to fungal infection in barley (Gjetting et al 2004); however, no information is available on their involvement in abiotic stress responses. Similarly, Barwin, which encodes a protein similar to the antifungal chitinbinding protein hevein isolated from rubber tree latex, is expressed in response to ethylene or viral infection (Pritsch et al 2000;Wu et al 2004). These data suggest that the increase in expression of Barwin observed in the in vitro cultured anthers is due to the abiotic stress treatment.…”

Phylogenomic Relationships of Rice Oxalate Oxidases to the Cupin Superfamily and Their Association with Disease Resistance QTL

“…GLPs have a variety of functions (Zhou et al 1998;Faris et al 1999;Druka et al 2002;Ramalingam et al 2003;Liu et al 2004;Wu et al 2004;Manosalva et al 2008). For example, a GLP, PSGER1, in peas shows sequence similarity to the Nterminal sequence of a putative plant receptor for rhicadhesin, a bacterial attachment protein (Gucciardo et al 2007).…”

“…OXOs and GLPs have been implicated in quantitatively inherited disease resistance in rice (Faris et al 1999;Ramalingam et al 2003;Liu et al 2004;Wu et al 2004). In some rice germplasms, GLPs contributed to a major effect QTL on chromosome 8.…”

AB-QTL analysis in spring barley: II. Detection of favourable exotic alleles for agronomic traits introgressed from wild barley (H. vulgare ssp. spontaneum)

“…Since QTL detection is carried out in advanced backcross populations, problems associated with considerable phenotypic variation and linkage drag in interspecific crosses are reduced. So far, several reports on the application of the AB-QTL strategy are available for tomato Fulton et al 1997Fulton et al , 2000Fulton et al , 2002Bernacchi et al 1998); rice (Xiao et al 1996(Xiao et al , 1998Moncada et al 2001;Brondani et al 2002;Septiningsih et al 2003;Wu et al 2004); maize (Ho et al 2002); pepper (Rao et al 2003); wheat (Huang et al 2003andbarley (Pillen et al 2003, 2004;Matus et al 2003;Li et al 2004). The favourable effects of the wild barley accession ISR101-23 on yield in two barley feeding varieties recorded by Pillen et al (2003Pillen et al ( , 2004 encourage further investments in the development of AB-populations for the genetic exploitation of diverse exotic barley germplasms.…”