Characterization of Two QTLs Controlling Resistance to Rice Stripe Virus Detected in a Japanese Upland Rice Line, Kanto 72

Abstract

The effects of two quantitative trait loci (QTLs) controlling the resistance to rice stripe virus (RSV) identified in a Japanese upland rice line, Kanto 72, (URK 72) were evaluated using near-isogenic lines (NILs). Two NILs carrying a single QTL (QTL-NILs) on chromosomes 2 and 11, respectively, were developed by markerassisted selection (MAS). The target QTL regions were introduced from the donor parent, Chugoku 40, which was bred from URK 72, into the genetic background of Koshihikari. Another line, which was a combined QTL-NIL, was developed from the cross between the two QTL-NILs to analyze the interaction of the two QTLs. Investigation of RSV resistance using the three NILs revealed that the effects of the two QTLs clearly differed in the reaction to RSV. The QTL on chromosome 11 exerted a major effect on reducing the infection rate of RSV. Although the QTL on chromosome 2 did not affect the infection rate, the symptoms of the diseased plants were milder. The combined QTL-NIL displayed a high level of resistance to RSV, while the infection rate and the symptom types of the diseased plants were similar to those of URK 72 or Chugoku 40. Since the major agronomic characters of the three QTL-NILs were the same as those of Koshihikari, these QTL-NILs were considered to be useful gene sources for RSV resistance rice breeding.

STV11 encodes a sulphotransferase and confers durable resistance to rice stripe virus

“…Previous mapping and allelic test suggested that both Stvb-i and Stvb are either tightly linked to or allelic with STV11 (refs 5, 8, 25). Intriguingly, our sequence analysis showed that Modan and Kanto 72, as well as their RSV-resistant offspring cultivars sequenced in this study all harbour the STV11-R allele (Supplementary Table 3), providing further support for their allelism.…”

Identification and validation of a major QTL for salt tolerance in soybean

“…This method was successfully used to validate QTL when NILs were generated by backcrosses using one of the QTL mapping population parents as the recurrent parent (Wissuwa and Ae 2001;Maeda et al 2006;Delourme et al 2008). However, developing of NIL S by backcrossing is extremely laborious, especially in the case of soybean, because of the low successful hybridization rate.…”

Quantitative Trait Loci Associated with Resistance to Rice Stripe Virus and Small Brown Planthopper Infestation in Rice

“…Stva (St1) and Stvb (St2) are two complementary dominant major genes which confer RSV resistance (Washio et al, 1968a(Washio et al, , 1968b. A number of RSV resistance QTL have also been reported in recent years (Ding et al, 2004, Maeda et al, 1999, Ding et al, 2005, Wu et al, 2009; these were mapped to various rice chromosomes, but only two have been properly validated to date (Maeda et al, 2004(Maeda et al, , 2006. A number of RSV resistance QTL have also been reported in recent years (Ding et al, 2004, Maeda et al, 1999, Ding et al, 2005, Wu et al, 2009; these were mapped to various rice chromosomes, but only two have been properly validated to date (Maeda et al, 2004(Maeda et al, , 2006.…”