Further Information on the Genetic Variation of Indigenous Rice Varieties in Yunnan Province, China.

Genetic variation is a principal concern for the plant breeders. Genetic variation and relationship among high yielding rice varieties viz. Binadhan 4, Binadhan 5, Binadhan 6, Binasail, BRRI dhan28 and BRRI dhan29 were analyzed using four decamer random primers. Polymerase Chain Reaction (PCR) amplified 22 RAPD markers, of which 18 (81.82%) were polymorphic. The proportion of polymorphic loci and the gene diversity values were 59.09% and 0.25 for the Binadhan 4; 59.09% and 0.21 for Binadhan 6; 54.55% and 0.23 for Binasail; 54.55% and 0.19 for BRRI dhan29; 50.00% and 0.19 for Binadhan 5 and 45.45% and 0.18 for BRRI dhan28, respectively. The coefficient of gene differentiation (Gst) across all loci was calculated as 0.35 reflecting the existence of high level of genetic variation among the six modern rice varieties. UPGMA dendrogram based on Neis genetic distance segregated the six high yielding rice varieties into two clusters: all four mutant varieties viz. Binadhan 4, Binadhan 5, Binadhan 6 and Binasail formed one cluster and two varieties of BRRI grown in boro season, BRRI dhan28 and BRRI dhan29 grouped together in another cluster. Among the mutants, two boro season varieties, developed from the same parent, Binadhan 5 and Binadhan 6 grouped together with genetic distance of 0.10. Therefore, RAPD offer a reliable method to evaluate genetic variation and relatedness among the high yielding rice varieties.DOI: http://dx.doi.org/10.3329/bjpbg.v21i1.17042

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Population Structure of 93 Varieties of Rice ( Oryza Sativa L. subsp. Hsien Ting) in Qinba, China

10.21203/rs.3.rs-113864/v1 ◽

2020 ◽

Author(s):

Yu Zhang ◽

Ye wen Wang ◽

Yue xing Wang ◽

Shi mao Zheng ◽

Wan ying Zhou ◽

...

Keyword(s):

Population Structure ◽

Genetic Variation ◽

Agronomic Traits ◽

Distance Matrix ◽

Mantel Test ◽

Rice Varieties ◽

Genetic Distance Matrix ◽

History Of ◽

Variation Explained ◽

Population Genetic Variation

Abstract BackgroundThe Qinba region is the transition region between indica and japonica varieties with a long history of indica varieties planting. 72,824 SNPs data based on GBS method, 48 pairs core primers of SSRs, and 15 agronomic traits were employed to explore the population structure of 93 rice varieties. The Mantel test was used to analyze the distance matrix generated using NlaIII-GBS only, MseI-GBS only, by combining NlaIII-GBS and MseI-GBS data and SSR.ResultIn this study, a total of 379 alleles were obtained using 48 pairs core primer of SSR, encompassing an average of 8.0 alleles per primer. The PPB and PIC was 88.65% and 0.77, respectively. Among these, RM278 possess the highest TNB and NPB, and the PPB in 29 pairs of SSR markers was 100%. RM176 showed the highest PIC. MAF was set to 0.05, and 39,872, 35,547 and 67,621 SNPs were obtained via NlaIII-GBS only, MseI-GBS only, and merged NlaIII-GBS and MseI-GBS data, respectively. The IBS genetic similarity coefficient average was 0.74. The results showed that the correlation between the genetic distance matrix based on NlaIII-GBS and MseI-GBS was the largest (R2=0.88), followed by NlaIII-GBS and SSR (R2=0.35), then by merged NlaIII-GBS and MseI-GBS data and SSR (R2=0.33), and the smallest by MseI-GBS and SSR (R2=0.27). The results showed that the 93 rice varieties could be clustered into two subgroups. Molecular variance analysis revealed that the genetic variation was 2% among populations and 98% within populations. Tajima’s D value was 1.66, and the FST between the two populations was 0.61, and the Nm was 0.16.ConclusionThe population genetic variation explained by SNP was larger than that explained by SSR. Through cluster analysis, the 93 samples were divided into 2 subgroups, with more than 97% of the samples clustered into one subgroup. The gene flow of 93 samples used in this study is larger than that of naturally self-pollinated crops, which may be caused by long-term breeding selection of indica varieties in the Qinba region. However, the genetic structure of the rice population is simple and lacked rare alleles.

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A rice gene that confers broad-spectrum resistance to β-triketone herbicides

Science ◽

10.1126/science.aax0379 ◽

2019 ◽

Vol 365 (6451) ◽

pp. 393-396 ◽

Cited By ~ 16

Author(s):

Hideo Maeda ◽

Kazumasa Murata ◽

Nozomi Sakuma ◽

Satomi Takei ◽

Akihiko Yamazaki ◽

...

Keyword(s):

Genetic Variation ◽

Broad Spectrum ◽

Rice Variety ◽

Rice Cultivars ◽

Rice Gene ◽

Rice Varieties ◽

Herbicide Resistant ◽

Broad Spectrum Resistance ◽

Varietal Improvement ◽

Triketone Herbicides

The genetic variation of rice cultivars provides a resource for further varietal improvement through breeding. Some rice varieties are sensitive to benzobicyclon (BBC), a β-triketone herbicide that inhibits 4-hydroxyphenylpyruvate dioxygenase (HPPD). Here we identify a rice gene, HIS1 (HPPD INHIBITOR SENSITIVE 1), that confers resistance to BBC and other β-triketone herbicides. We show that HIS1 encodes an Fe(II)/2-oxoglutarate–dependent oxygenase that detoxifies β-triketone herbicides by catalyzing their hydroxylation. Genealogy analysis revealed that BBC-sensitive rice variants inherited a dysfunctional his1 allele from an indica rice variety. Forced expression of HIS1 in Arabidopsis conferred resistance not only to BBC but also to four additional β-triketone herbicides. HIS1 may prove useful for breeding herbicide-resistant crops.

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