Mapping of quantitative trait loci associated with ultraviolet-B resistance in rice (Oryza sativa L.)

Abstract

The detection of quantitative trait loci (QTLs) associated with UV-B resistance in rice should allow their practical application in breeding for such a complex trait, and may lead to the identification of gene characteristics and functions. Considerable variation in UV-B resistance exists within cultivated rice (Oryza sativa L.), but its detailed genetic control mechanism has not been well elucidated. We detected putative QTLs associated with the resistance to enhanced UV-B radiation in rice, using 98 BC(1)F(5) (backcross inbred lines; BILs) derived from a cross between Nipponbare (a resistant japonica rice variety) and Kasalath (a sensitive indica rice variety). We used 245 RFLP markers to construct a framework linkage map. BILs and both parents were grown under visible light with or without supplemental UV-B radiation in a growth chamber. In order to evaluate UV-B resistance, we used the relative fresh weight of aerial parts (RFW) and the relative chlorophyll content of leaf blades (RCC). The BIL population exhibited a wide range of variation in RFW and RCC. Using composite interval mapping with a LOD threshold of 2.9, three putative QTLs associated with both RFW and RCC were detected on chromosomes 1, 3 and 10. Nipponbare alleles at the QTLs on chromosome 1 and 10 increased the RFW and RCC, while the Kasalath allele at the QTL on chromosome 3 increased both traits. Furthermore, the existence of both QTLs on chromosomes 1 and 10 for UV-B resistance was confirmed using chromosome segment substitution lines. Plants with Kasalath alleles at the QTL on chromosome 10 were more sensitive to UV-B radiation than plants with them on chromosome 1. These results also provide the information not only for the improvement of UV-B resistance in rice though marker-associated selection, but also for the identification of UV-B resistance mechanisms by using near-isogenic lines.

Development of mini core collection of Japanese rice landrace

“…The heading date and waxiness of the grain (Olsen et al 2006) are thought to be artificially selective traits. As QTLs in upland/ lowland marker regions, QTL for phosphorous sensitivity (Wissuwa et al 1998) near RM207, field resistance for rice blast near RM418 (Tabien et al 2002), spikelet number, amylose content (Cui et al 2002) and allelopathy (Ebana et al 2001) near RM412, UV-B resistance (Sato et al 2003) near RM516, culm strength under upland conditions (Mu et al 2004) near RM440, were reported. These QTLs seem related to the upland and lowland cultivation conditions or differences among the morphological differences of upland and lowland varieties.…”

Construction and Evaluation of Chromosome Segment Substitution Lines Carrying Overlapping Chromosome Segments of indica Rice Cultivar 'Kasalath' in a Genetic Background of japonica Elite Cultivar 'Koshihikari'

“…In contrast, the uniformity of the genetic background of each CSSL enabled to rapidly proceed to the linkage mapping of target QTLs. We have already revealed the advantages of these CSSLs in the analysis of resistance to ultraviolet-B radiation (Sato et al 2003, Ueda et al 2004, the response of rice to Al (Ma et al 2002), and seed longevity (Miura et al 2002).…”

Ultraviolet-Defense Mechanisms in Higher Plants

“…The study identified three QTLs on chromosomes 1, 3 and 10. Among them, qUVR-10, a qtl for UVB resistance on chromosome 10, showed the largest effect (the percentage of variance explained was approximately 40%) and plants homozygous for the "Nipponbare" allele at this QTL locus were more resistant to UVB compared with those homozygous for the "Kasalath" allele (63). After the QTL cloning, qUVR-10 was shown to encode cPD photolyase (72,73).…”