Segregation distortion detected in six rice F₂populations generated from reciprocal hybrids at three altitudes

Abstract

This paper presents investigations of segregation distortion of six rice F2 populations generated from reciprocal F1 hybrids grown at three locations varied at altitudes from 400 to 2200 m. The F1s were derived from reciprocal crosses between cv. XMG, which is a japonica landrace traditionally grown at 2650 m altitude, and cv. N34, which is a japonica restorer possessing a fertility restoring (Rf) gene and cytoplasm of male sterility (CMS) donated by an indica cultivar. Among nine morphological traits of the F2 populations, only one was in normal distribution, eight were distorted in all or at least one population. Out of 16 polymorphic PCR markers, 10 markers distributed on 7 chromosomes were significantly distorted. Among these markers, RMAN7 and RM257 were distorted in both of the reciprocal populations, which suggested that nuclear genes had strong effects on segregation distortion. The other makers were distorted only in the populations with cytoplasm donated by XMG or N34. The results indicated that segregation of DNA markers was affected by cytoplasm background. Segregation distribution was also affected by altitude, since segregation distortions of most of the markers were detected not in all the three populations generated from F1 grown at the three altitudes, but only in one population from F1 grown at one altitude. Marker M45461, which is located within Rf-1 locus, was severely distorted towards N34 in all the populations with cytoplasm donated by N34, but not in the populations with cytoplasm provided by XMG. The results indicated that interaction between CMS and Rf gene had strong effects on distortion. Results of this study indicated that japonica cytoplasm did not cause distortion favouring a special parent, but indica cytoplasm made distortion favouring a maternal parent. The results suggested that indica cytoplasm was not well compatible with japonica nuclear background, while japonica cytoplasm did not have such trouble with indica nuclei. This study also found that the six F2 populations were divergent into two groups due to difference of cytoplasm background.

The maternal cytoplasmic environment may be involved in the viability selection of gametes and zygotes

“…The direction of the distortion was selectively biased to F344 homozygotes in the WKY cytoplasm. In rice, Wang et al (2009) found that the japonica cytoplasm did not cause any distortion favouring a special parent, but that the indica cytoplasm favoured the maternal parent, which suggested that the indica cytoplasm was incompatible with a japonica nuclear background and that the japonica cytoplasm did not have such trouble with the indica nuclei. These results suggested that one of the cytoplasms in each case favoured the nucleus allele originating in the other inbred line and that the other cytoplasm showed no consistent bias.…”

“…In invertebrates, Sinkins (2011) found a new embryo-killing gene that causes post-segregation distortion. In addition, mapping populations, genetic transmission, non-homologous recombination, gene transfer, transposable elements, reproductive isolation, environmental agents and non-biological factors, such as sample size, marker type and genotyping errors, are all possible causes for the observed segregation distortion (Xu et al, 1997;Wang et al, 2009;Phadnis, 2011). However, the most promising explanation is viability selection occurring at the markers or loci linked to the markers observed to have distorted inheritance (Vogl and Xu, 2000).…”

Genetic Map Construction and Functional Characterization of Genes within the Segregation Distortion Regions (SDRs) in the F2:3 Populations Derived from Wild Cotton Species of the D Genome

“…have been reported in a number of plants such as rice (Wang et al 2009), and therefore detection of SDRs in the two populations developed from the two wild parental lines is a common feature more so among the F 2:3 population. It is assumed based on Mendelian law that there is an equal probability of transmission of alleles from either parent during sexual reproduction, but this has not been the case in several studies, being there tend to be phenomena referred to the preferential transmission of alleles or genotypes known as segregation distortion (SD) (Nadeau 2017).…”

Exploring the genetic characteristics of 93-11 and Nipponbare recombination inbred lines based on the GoldenGate SNP assay

“…Rice consists of two major subspecies, indica and japonica, which were respectively designated as "Hsien" and "Keng" in China approximately 2,000 years ago (Ouyang et al, 2009). Abundant genetic diversity between subspecies, or ecotypes derived from different geographical environments, or ecotypes with different characteristics have led to numerous rice varieties worldwide (Wang et al, 2009). The indica and japonica subspecies vary in many important aspects during their growth and development process, including leaf color, apiculus hair length, and grain shape (Ouyang et al, 2009).…”