The contribution of intersubspecific hybridization to the breeding of super-high-yielding japonica rice in northeast China.
Hybridization between indica and japonica rice combined with utilization of ideal plant type has led to the development of high-yielding japonica rice in northern China. However, the contribution at the genomic level of intersubspecific hybridization to the increased yield of northern Chinese japonica rice is uncertain. In this study, we analyzed the genomic pedigree of descendants of hybridization between indica and japonica rice grown in northeastern China between 1963 and 2008. Simple sequence repeat markers indicated that since 1990 the genetic diversity among northern japonica cultivars was enriched. Genome-wide analysis with subspecies-specific indel and intron length polymorphism markers showed indica-allele frequencies were significantly increased in cultivars bred after 1990, and were significantly positively correlated with spikelet number per panicle and significantly negatively correlated with panicle number per plant. Among eight genes controlling agronomic traits, GN1a and GS3 were partially fixed in the genome of northern japonica cultivars. In contrast, Waxy and qSH1 were eliminated, whereas DEP1 and qSW5 were retained. Indica germplasm is an important contributor to the increased yield of northern japonica rice. Breeding for high yield and grain quality in combination is a complicated process and difficult to achieve when relying on only one or several functional genes, thus the selection expertise of the breeder remains critical.
Key Laboratory of Northeast Rice Biology and Breeding, Ministry of Agriculture, Rice Research Institute, Shenyang Agricultural University, Dongling Road 120, Shenyang, 110866, China.
Jian
J
Sun
Di
D
Liu
Jia-Yu
JY
Wang
Dian-Rong
DR
Ma
Liang
L
Tang
Hong
H
Gao
Zheng-Jin
ZJ
Xu
Wen-Fu
WF
Chen
D000483:Alleles; D000595:Amino Acid Sequence; D001947:Breeding; D002681:China; D018556:Crops, Agricultural / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D005787:Gene Frequency; D017343:Genes, Plant; D014644:Genetic Variation; D005838:Genotype; D006824:Hybridization, Genetic; D054643:INDEL Mutation; D007438:Introns; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide
D018744:DNA, Plant