The hybrid breakdown 1(t) locus induces interspecific hybrid breakdown between rice Oryza sativa cv. Koshihikari and its wild relative O. nivara

Abstract

Reproductive barriers are often observed in progenies derived from crosses between relatively distant species, such as cultivated varieties and their wild relatives. Such barriers hinder the transfer of agronomically important genes from one species to another. In the process of constructing a series of introgression lines (ILs) between Oryza sativa japonica cv. Koshihikari and wild species O. nivara, we observed the occurrence of hybrid breakdown, a reproductive barrier observed in F 2 and later generations. Plants affected by this hybrid breakdown show extremely weak growth and die before heading. Linkage analysis and construction of ILs indicated that the locus -hbd1(t), located on the short arm of chromosome 2 of O. nivara, induces hybrid breakdown in the Koshihikari genetic background. hbd1(t) is identical to hbd1, which was previously identified in a cross between Koshihikari and Nona Bokra (indica) cultivars of O. sativa. We present genetic evidence that hbd1(t) regulates hybrid breakdown and its location within 50 kb. Possible reasons for this locus being responsible for hybrid breakdown in inter-and intraspecific crosses are discussed.

Gain of deleterious function causes an autoimmune response and Bateson–Dobzhansky–Muller incompatibility in rice

“…Thus, plant NBS-LRRs have a greater potential to establish hybrid weakness and to become an evolutionary force in plant speciation compared to other gene classes. Hybrid weakness has been reported not only in rice (Amemiya and Akamine 1963;Sato and Morishima 1988;Fukuoka et al 1998, Kubo and Yoshimura 2002Matsubara et al 2007;Yamamoto et al 2007;Miura et al 2008), but also in other plant species . Identifying the causal genes of this phenomenon in other plants will determine the validity of this hypothesis.…”

“…But in other plants, the physiological and molecular mechanisms for the appearance of weakness phenotype remain to be established. Rice has great potential to investigate and understand this phenomenon as weakness phenotype is observed in numerous intra and inter-specific crosses (Amemiya and Akamine 1963;Sato and Morishima 1988;Fukuoka et al 1998Fukuoka et al , 2005Kubo and Yoshimura 2002;Matsubara et al 2007;Yamamoto et al 2007;Miura et al 2008).…”

Chromosome Segment Substitution Lines: A Powerful Tool for the Introgression of Valuable Genes from Oryza Wild Species into Cultivated Rice (O. sativa)

“…Wide hybridization has been used for many years to introduce qualitative characters from wild species into elite breeding materials, such as disease and insect resistance, and male sterility (Brar and Khush 1997;Dalmacio et al 1995). However, several incompatibility barriers, such as low crossing success, increased sterility, and limited recombination between the chromosomes of wild and cultivated species seriously hampered the transfer of useful genes (Brar and Khush 1986;Fu et al 2008;Miura et al 2008). Recent advances in tissue culture and genomics helped the production of wide hybrids between distantly related species.…”

“…2 A backcross scheme for developing chromosome segment substitution lines (CSSL) utilizing molecular markers for selecting the progeny each generation. some researchers have chosen to develop CSSLs to introgress chromosome segments containing genes of interest from either indica or japonica cultivars into the desired genetic background (Harushima et al 2002;Oka 1988;Sano 1993) even though limited success was achieved because of high sterility or hybrid breakdown (Miura et al 2008;Win et al 2009). Reported successful intra-specific CSSLs include 'IR24', an indica donor parent, introgressed into 'Asominori', a japonica recurrent parent, in which alleles for some important quantitative traits were mapped including eating quality , grain dimension and chalkiness (Wan et al 2005;Wang et al 2007), grain length (Wan et al 2006), and the sterility gene, S31 (Zhao et al 2007).…”

Fine mapping and candidate gene analysis of a novel PANICLE AND SPIKELET DEGENERATION gene in rice

“…At heading, the two F 2 populations were individually phenotyped and 7307 homozygous recessive individuals with psd phenotypes in the two F 2 populations were identified for mapping analysis. Genomic DNA was extracted from mature leaves using the template preparation solution method described by Miura et al (2008).…”