RFLP-based phylogenetic analysis of wide compatibility varieties in Oryza sativa L.

Abstract

Twenty-one wide compatibility varieties (WCVs) of rice together with three indica and three japonica testers were assayed with 160 DNA probes that were selected to represent the entire RFLP map at an average interval of 11 cM. On the basis of four enzyme digestion 125 probes detected polymorphisms among the WCVs and subspecies' testers. Among these polymorphic probes there were 68 that could distinguish the indica from the japonica testers. Two dendrograms were constructed on the basis of 398 polymorphic fragments of 125 probes and 139 polymorphic fragments of 68 subspecies' differentiating probes in combination with single enzymes, respectively. The reliability and representativeness of the testers and the levels of DNA variations among WCVs were estimated. The potential of WCVs in the utilization of intersubspecific heterosis is discussed.

Through the genetic bottleneck: O. rufipogon as a source of trait-enhancing alleles for O. sativa

“…It is difficult to achieve reliable and economically viable levels of out-crossing during F1 hybrid seed production and as a result, hybrid rice breeding as a commercial enterprise is still in its infancy. Nonetheless, experience in hybrid rice breeding programs around the world highlights the value of indica · japonica combinations as a way of maximizing levels of heterosis, with the caveat that the associated sterility barriers must be overcome (Li and Yuan 2000;Zheng et al 1994).…”

Identification of an S 5 n allele in Oryza rufipogon Griff. and its effect on embryo sac fertility

“…Young leaves were collected from wild rice and genomic DNA was extracted according to the SDS simple extraction method of Zheng et al [11] with slight modification. (20 μL) PCR reactions (20 μL) included 20-30 ng template DNA, 0.15 μmol/L each primer, 0.2 mmol/L each dNTP, 1×PCR buffer, and 1 U Taq polymerase.…”

Genetic differentiation of wild relatives of rice as assessed by RFLP analysis

“…Total DNA extraction, restriction endonuclease digestion, electrophoresis, Southern blotting, hybridization and autoradiography were carried out following the methods described previously by Zheng et al (1990) and Lu and Zheng (1992). Thirty rice clones were selected based on our previous work on phylogenetic analysis of the cultivated O. sativa (Zheng et al 1994;Qian et al 1995), which are distributed over different chromosomes of the cultivated rice (see Table 2). Most clones (RG clones) are random genomic clones from Cornell University.…”