Geographic pattern of variation among Asian native rice cultivars (Oryza sativa L.) based on fifteen isozyme loci

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 782-792 ◽  
Author(s):  
J. C. Glaszmann
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Indian Subcontinent ◽  
Indica Rice ◽  
Japonica Rice ◽  
Geographic Pattern ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Himalayan Foothills

The geographic pattern of isozyme variation among rice varieties (Oryza sativa L.) in Asia is described based on an electrophoretic survey of 1688 accessions for 15 loci. The distribution patterns are strongly determined by the existence of several varietal groups that are characterized by contrasting multilocus types with dissimilar environmental and macrogeographic distributions. The two main groups correspond to the indica and japonica subspecies. Other types are frequently found in the Indian subcontinent, especially along the Himalayan foothills. These types are predominant in the Indus River basin. They are differentiated into four groups in the eastern part of the Himalayan foothills. There is variation within the groups. Non-random allele distributions are observed, such as regional clines and narrow localization of alleles. Diversity among indica rice is evenly distributed in whole tropical Asia. Variation among japonica rice shows the hilly part of continental Southeast Asia to be the region of highest genetic diversity and its probable area of origin. All this information provides a guide for further analysis aimed at elucidating the history of cultivated rice in Asia and, subsequently, in other continents.Key words: Asian rice, genetic diversity, isozymes, geographic distributions.

scholarly journals A large-scale analysis of seed natural aging revealed stronger aging resistance in weedy rice than coexisting cultivated rice for continuous 4 years across China

2019 ◽  
Author(s):  
weimin dai ◽  
Yuan Wang ◽  
Yu-Jie Zhang ◽  
Xi-Xi Sun ◽  
Jin-Ling Yang ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Large Scale ◽  
Oryza Sativa L ◽  
Germination Rate ◽  
Weedy Rice ◽  
Japonica Rice ◽  
Rice Cultivars ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Aging Resistance

Abstract Increasing resistance to aging is conducive to seed storage and germination rate of crop. Meanwhile, the resistance to aging is one of the important adaptive mechanisms of weed to thrive in farmland. Weedy rice (Oryza sativa f. spontanea) and cultivated rice (Oryza sativa L.) provide a unique pair demonstrating a weed and conspecific model crop that can be used to study the aging resistance of plants across a diverse geographical range. Chinese weedy rice derived from de-domestication of cultivated rice has rapidly risen to malignant weeds, though the hazard has only been reported for about 20 years. Whether weedy rice rapidly evolves higher seed aging resistance than cultivated rice during the process of dedomestication, which is conducive to its persistence in rice fields, is still unclear. In this experiment, the seeds of weed rice populations and their co-existing rice varieties were collected from 61 regions of China and germinated under normal and high temperatures for consecutive four years (2013–2016). Our study found that the aging resistance of weedy rice was higher than that of the co-existing rice cultivars, and weedy rice may have evolved a different aging resistance mechanism than rice cultivars and could be used as a germplasm resource to cultivate aging-resistant rice. The indica-type has strong aging resistance and no dormancy, while the japonica type has weak aging resistance and a little weak dormancy. Thus, by introducing indica-type aging-resistant alleles into japonica rice, cultivation of aging-resistant japonica rice could be possible.

Extraordinarily polymorphic ribosomal DNA in wild and cultivated rice

Genome ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 1109-1116 ◽  
Author(s):  
K. D. Liu ◽  
Qifa Zhang ◽  
G. P. Yang ◽  
M. A. Saghai Maroof ◽  
S. H. Zhu ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Ribosomal Dna ◽  
Wild Rice ◽  
Indica Rice ◽  
Intergenic Spacer ◽  
Oryza Rufipogon ◽  
Japonica Rice ◽  
Cultivated Rice ◽  
Spacer Length ◽  
Origin And Evolution

A collection of 481 rice accessions was surveyed for ribosomal DNA (rDNA) intergenic spacer length polymorphism to assess the extent of genetic diversity in Chinese and Asian rice germplasm. The materials included 83 accessions of common wild rice, Oryza rufipogon, 75 of which were from China; 348 entries of cultivated rice (Oryza sativa), representing almost all the rice growing areas in China; and 50 cultivars from South and East Asia. A total of 42 spacer length variants (SLVs) were detected. The size differences between adjacent SLVs in the series were very heterogeneous, ranging from ca. 21 to 311 bp. The 42 SLVs formed 80 different rDNA phenotypic combinations. Wild rice displayed a much greater number of rDNA SLVs than cultivated rice, while cultivated rice showed a larger number of rDNA phenotypes. Indica and japonica groups of O. sativa contained about equal numbers of SLVs, but the SLV distribution was significantly differentiated: indica rice was preferentially associated with longer SLVs and japonica rice with shorter ones. The results may have significant implications regarding the origin and evolution of cultivated rice, as well as the inheritance and molecular evolution of rDNA intergenic spacers in rice. Key words : rDNA, Oryza rufipogon, Oryza sativa, germplasm diversity, evolution.

scholarly journals The Development and Characterization of Near-Isogenic and Pyramided Lines Carrying Resistance Genes to Brown Planthopper with the Genetic Background of Japonica Rice (Oryza sativa L.)

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 498
Author(s):  
Cuong D. Nguyen ◽  
Holden Verdeprado ◽  
Demeter Zita ◽  
Sachiyo Sanada-Morimura ◽  
Masaya Matsumura ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Resistance Genes ◽  
Genetic Background ◽  
Oryza Sativa L ◽  
Rice Variety ◽  
Brown Planthopper ◽  
Nilaparvata Lugens ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Nilaparvata Lugens Stål

The brown planthopper (BPH: Nilaparvata lugens Stål.) is a major pest of rice, Oryza sativa, in Asia. Host plant resistance has tremendous potential to reduce the damage caused to rice by the planthopper. However, the effectiveness of resistance genes varies spatially and temporally according to BPH virulence. Understanding patterns in BPH virulence against resistance genes is necessary to efficiently and sustainably deploy resistant rice varieties. To survey BPH virulence patterns, seven near-isogenic lines (NILs), each with a single BPH resistance gene (BPH2-NIL, BPH3-NIL, BPH17-NIL, BPH20-NIL, BPH21-NIL, BPH32-NIL and BPH17-ptb-NIL) and fifteen pyramided lines (PYLs) carrying multiple resistance genes were developed with the genetic background of the japonica rice variety, Taichung 65 (T65), and assessed for resistance levels against two BPH populations (Hadano-66 and Koshi-2013 collected in Japan in 1966 and 2013, respectively). Many of the NILs and PYLs were resistant against the Hadano-66 population but were less effective against the Koshi-2013 population. Among PYLs, BPH20+BPH32-PYL and BPH2+BPH3+BPH17-PYL granted relatively high BPH resistance against Koshi-2013. The NILs and PYLs developed in this research will be useful to monitor BPH virulence prior to deploying resistant rice varieties and improve rice’s resistance to BPH in the context of regionally increasing levels of virulence.

scholarly journals Variability in Nutraceutical Lipid Content of Selected Rice (Oryza sativa L. spp. indica) Germplasms

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 823 ◽  
Author(s):  
Bhornchai Harakotr ◽  
Kasidid Prompoh ◽  
Supakorn Boonyuen ◽  
Bhalang Suriharn ◽  
Kamol Lertrat
Keyword(s):  
Oryza Sativa ◽  
Lipid Content ◽  
Oryza Sativa L ◽  
Indica Rice ◽  
Block Design ◽  
Added Value ◽  
Rice Varieties ◽  
Breeding Programs ◽  
Lipid Contents ◽  
Lipid Compounds

Rice (Oryza sativa L.) contains many high-value nutritional compounds, including nutraceutical lipid compounds that offer health benefits. An understanding of the genetic variability in the lipid contents of different rice germplasms is necessary to support breeding programs. The goals of this study were: i) to investigate varietal differences in levels of the nutraceutical lipid α-tocopherol, γ-oryzanol, campesterol, β-sitosterol, octacosanol, and squalene and ii) to identify clusters of rice germplasms based on their lipid contents. Eighty-three indica rice subspecies were evaluated using a randomized complete block design with three replications. Research was conducted in Thailand during the 2016 rice-growing season. Significant differences were found among genotypes across all traits. The largest variation was found for β-sitosterol, followed by campesterol, octacosanol, and α-tocopherol. Variation in squalene content was small. Four principal components were found that accounted for 93.47% of overall variability. β-sitosterol, campesterol, and squalene were the principal discriminatory constituents. No significant correlation was found between color parameters and levels of these compounds, suggesting that former are of little use as an indirect marker for selection of fat-soluble nutraceuticals. Cluster analysis sorted the germplasm into nine clusters, based on their nutraceutical lipid content. TU-010, TU-027, TU-093, and TU-244 genotypes had the highest levels, making them a potentially useful genetic resource in breeding programs for nutraceutically-improved rice. The findings of this study can support the introduction of novel rice varieties with high added-value bioactive properties.

scholarly journals Origin of the Aromatic Group of Cultivated Rice (Oryza sativa L.) Traced to the Indian Subcontinent

2019 ◽  
Vol 11 (3) ◽  
pp. 832-843 ◽  
Author(s):  
Peter Civáň ◽  
Sajid Ali ◽  
Riza Batista-Navarro ◽  
Konstantina Drosou ◽  
Chioma Ihejieto ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Indian Subcontinent ◽  
Cultivated Rice ◽  
Aromatic Group

scholarly journals Construction of vector and transformation of drought-responsive gene OsNAC1 into J02 (Oryza sativa L. Japonica) rice

2016 ◽  
Vol 14 (2) ◽  
pp. 271-277
Author(s):  
Phạm Thu Hằng ◽  
Đàm Quang Hiếu ◽  
Phan Tuấn Nghĩa ◽  
Phạm Xuân Hội
Keyword(s):  
Transcription Factor ◽  
Oryza Sativa ◽  
Stress Responses ◽  
Transcriptional Activation ◽  
Oryza Sativa L ◽  
Terminal Region ◽  
Cauliflower Mosaic Virus ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Gm Plants

NAC (including NAM - no apical meristem, ATAF1/2 - Arabidopsis transcription activation factor and CUC2 - cup-shaped cotyledon), which is the largest plant transcription factor family, plays an important role in development and stress responses in plants. Protein of this family is characterized by a highly conserved DNA binding domain, known as NAC domain in the N-terminal region. In contrast, the C-terminal region of NAC proteins, usually containing the transcriptional activation domain, is highly diversified both in length and sequence. More than 100 members of this family have been identified in rice. However, only a few of them have been functionally characterized, especially in rice. Gene encoding transcription factor OsNAC1 has been proved to play an important role in drought stress in plants. The CaMV35S promoter derived from the common plant virus, cauliflower mosaic virus (CaMV), is a component of transgenic constructs in more than 80% of genetically modified (GM) plants. It is the promoter of choice for plant genetic engineering, as it is a strong and constitutive promoter. In this study, an expression vector harboring OsNAC1 in the form of CaMV35S:OsNAC1:Nos was constructed and transferred into J02 (Oryza sativa L. Japonica) rice plants via Agrobacterium tumefaciens. The presence of the transgene was confirmed by PCR using OsNAC1 specific primers. T0 CaMV35S:OsNAC1:Nos transgenic lines were selected from transgenic plants. The obatained results are expected to be further exploited for development of stress tolerant rice varieties in the future.

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