scholarly journals Allelic variations in aroma gene in cultivated rice varieties

2020 ◽  
Vol 28 (2) ◽  
pp. 241-254
Author(s):  
A. Akwero ◽  
D. Ocan ◽  
W. Akech ◽  
J. Lamo ◽  
M. Ochwo-Ssemakula ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Crop Improvement ◽  
Breeding Programme ◽  
Functional Markers ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Economically Valuable Traits ◽  
New Varieties ◽  
Allelic Variations ◽  
Badh2 Gene

Germplasm is a valuable source of genetic diversity that supports crop improvement efforts in any breeding programme but it must first be fully characterised for economically valuable traits before it can be effectively utilised. In rice (Oryza sativa), the development of new varieties with improved aroma requires correct phenotyping and prior knowledge of the available genes and alleles governing the aroma trait in the gene pool. Correct phenotyping and genotyping can be achieved using sensory methods and functional markers associated with polymorphisms that define the aroma genes. The objective of this study was to evaluate the aroma status of rice accessions and to assess for the various alleles of badh2 gene using functional markers. A total of 56 rice accessions were evaluated at National Crops Resources Research Institute (NaCRRI) in Uganda for their aroma using sensory methods and a molecular marker to differentiate between aromatic and non- aromatic accessions. The aromatic accessions were then evaluated for variations within the betaine aldehyde dehydrogenase2 (badh2) gene responsible for aroma in rice using functional markers. Sensory evaluation of aroma identified 23 accessions to be aromatic; while 33 were non-aromatic. Molecular results identified 20 accessions as aromatic; while 36 accessions were non-aromatic. Functional marker analysis indicated the presence of badh2-E7 allele in 20 aromatic accessions within this collection that could be employed in the breeding programme for the rice aromatic trait. Key words: badh2 alleles, functional markers, Oryza sativa

scholarly journals Studies on Aroma Gene and its Application in Rice Genetics and Breeding

2018 ◽  
Vol 7 (2) ◽  
pp. 29 ◽  
Author(s):  
Bo Peng ◽  
Yu-Han Zuo ◽  
Yan-Lin Hao ◽  
Juan Peng ◽  
Dong-Yan Kong ◽  
...  
Keyword(s):  
Oryza Sativa L ◽  
Rapid Development ◽  
Functional Markers ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Sustained Development ◽  
Great Progress ◽  
New Varieties ◽  
Rice Genetics ◽  
Made In

Rice (Oryza sativa L.) is one of the most important food crops in the world, and the staple food for more than half of the world’s population. Along with the sustained development of living standards, people’s demand for high quality rice is increasing. As one of the types of cultivated rice, aromaticrice is preferred by most of the consumers because of its agreeable scent. With the rapid development of rice functional genomics and sequencing technology, great progress has been made in understanding the aroma gene in rice, and a series of functional markers has been developed for screening the aroma gene and breeding new rice varieties in recent years. This paper mainly reviews the progress in the genetic basis, gene function and regulation of the aroma gene, and the application of aroma gene functional markers in the genetic improvement and breeding of aromaticrice. Thus, it provides important references for the cultivation of new varieties of aromaticrice.

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.

scholarly journals Increased Regeneration Efficiency in Seed Derived Callus of Rice (Oryza sativa L.)

1970 ◽  
Vol 16 (1) ◽  
pp. 45-52
Author(s):  
AKM Mohiuddin ◽  
Shahanaz Sultana ◽  
Jannatul Ferdous
Keyword(s):  
Oryza Sativa ◽  
The Other ◽  
Regeneration Ability ◽  
Cultivated Rice ◽  
High Concentration ◽  
Rice Varieties ◽  
Rooting Ability ◽  
Regenerated Plants ◽  
Regeneration Efficiency ◽  
Callus Type

In five cultivated rice varieties e.g., Nonabokra, PNR 381, Taipei 309, Koshika and TKM 11 the response in the initiation of callus and its size varied greatly among varieties, salt concentrations (NaCl and Na2SO4) and their interaction. Better regeneration ability of Nonabokra, Koshika and TKM 11 was found to be correlated to small size callus with a high concentration of Na2SO4. The regeneration ability found here was dependent on variety/genotype, callus type and size, source of salt and their concentration. Regeneration ability enhanced three - tenfolds from Na2SO4 stressed callus compared to the control i.e. without Na2SO4. Vigorous rooting was also observed in the regenerated plants obtained from the calli induced in the medium containing Na2SO4. In NaCl supplemented medium, on the other hand, regeneration and rooting ability were poor.Key words: Rice varieties, Regeneration efficiency, Shoot regenerationDOI = 10.3329/ptcb.v16i1.1105Plant Tissue Cult. & Biotech. 16(1): 45-52, 2006 (June)

scholarly journals Genetic dissection of eating and cooking qualities in different subpopulations of cultivated rice (Oryza sativa L.) through association mapping

BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Chunfang Zhao ◽  
Ling Zhao ◽  
Qingyong Zhao ◽  
Tao Chen ◽  
Shu Yao ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Association Mapping ◽  
Genetic Factors ◽  
Amylose Content ◽  
Starch Synthesis ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Gene Markers ◽  
A Genome ◽  
Gel Consistency

Abstract Background Eating and cooking qualities (ECQs) of rice (Oryza sativa L.) determine consumer acceptance and the economic value of rice varieties. The starch physicochemical properties, i.e. amylose content, gel consistency, gelatinization temperature and pasting viscosity are important indices for evaluating rice ECQs. Genetic factors are required for development of rice varieties with excellent ECQs and association mapping is one of the promising approaches for discovering such associated genetic factors. Results A genome-wide association mapping was performed on a set of 253 non-glutinous rice accessions consisting of 83 indica and 170 japonica cultivated rice varieties through phenotyping for 11 ECQ traits in two consecutive years and genotyping with 210 polymorphic SSR and candidate-gene markers. These markers amplified 747 alleles with an average of 3.57 alleles per locus. The structure, phylogenetic relationship, and principal component analysis indicated a strong population differentiation between indica and japonica accessions and association mapping was thus undertaken within indica and japonica subpopulations. All traits showed a large phenotypic variation and highly significant phenotypic correlations were present between most of traits. A total of 33 and 30 loci were located for 11 ECQs in indica and japonica subpopulations respectively. Most of associated loci were overlapped with starch synthesis-related genes (SSRGs), and the Wx locus gathered 14 associated loci with the largest effects on amylose content, gel consistency and pasting viscosities. Eight subpopulation specific markers, RM588, Wx-(CT)n, SSI and SBE1 for indica subpopulation and RM550, Wxmp, SSIIa and SBE4 for japonica subpopulation, were identified, suggesting alleles of SSRGs showed the subspecific tendency. Nevertheless, allelic variation in SSIIa showed no tendency towards subspecies. One associated maker RM550 detected in japonica subpopulation for amylose content and pasting viscosity was verified a potential novel and stably expressed locus and could be selected for further fine mapping. Conclusion This study illustrated the potential for dissecting genetic factors of complex traits in domesticated rice subspecies and provided highly associated markers to facilitate marker-assisted selection for breeding high-quality indica or japonica rice varieties.

scholarly journals Genetic relationships and diversity of weedy rice (Oryza sativa L.) and cultivated rice varieties in Okayama Prefecture, Japan

2009 ◽  
Vol 59 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Maiko Akasaka ◽  
Jun Ushiki ◽  
Hiroyoshi Iwata ◽  
Ryuji Ishikawa ◽  
Toshio Ishii
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Genetic Relationships ◽  
Weedy Rice ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Okayama Prefecture

scholarly journals Agro-morphological diversity (quantitative traits) of rice (Oryza sativa L.) cultivated in Baglung District, Nepal

2018 ◽  
Vol 6 ◽  
pp. 52-57
Author(s):  
Hom Nath Pathak
Keyword(s):  
Oryza Sativa ◽  
Quantitative Traits ◽  
Oryza Sativa L ◽  
Crop Improvement ◽  
Germplasm Conservation ◽  
Morphological Diversity ◽  
Morphological Characters ◽  
Cultivated Rice ◽  
Rice Landraces ◽  
Quantitative Characters

Agro-morphological traits are the features of cultivated rice i.e. Oryza sativa L. Rice landraces differ from the other landrace in morphological features such as grain weight, culm number, and height of the plant. Nineteen different landraces of cultivated rice from Paiyunpata village, Baglung were studied and their quantitative characters were measured. The most varied landraces in morphological characters (Khate, Rato, Nepale, Anadi etc. i.e. species far from quadrants in PCA) are suggested for crop improvement. Findings from this research could be helpful for germplasm conservation.

scholarly journals Microsatellite diversity within Oryza sativa with emphasis on indica–japonica divergence

2005 ◽  
Vol 85 (1) ◽  
pp. 1-14 ◽  
Author(s):  
LI-ZHI GAO ◽  
CHI-HONG ZHANG ◽  
LI-PING CHANG ◽  
JI-ZENG JIA ◽  
ZONG-EN QIU ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa ◽  
Gene Diversity ◽  
Rice Genome ◽  
Chromosome 1 ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Allele Number ◽  
Clustering Patterns ◽  
Microsatellite Diversity

The molecular evolution of cultivated rice Oryza sativa L. has long been a subject of rice evolutionists. To investigate genetic diversity within and differentiation between the indica and japonica subspecies, 22 accessions of indica and 35 of japonica rice were examined by five microsatellite loci from each chromosome totalling 60 loci. Mean gene diversity value in the indica rice (H=0·678) was 1·18 times larger than in the japonica rice (H=0·574). Taking the sampling effect into consideration, average allele number in the indica rice was 1·40 times higher than that in the japonica rice (14·6 vs 10·4 per variety). Chromosome-based comparisons revealed that nine chromosomes (1, 2, 3, 4, 5, 8, 9, 10 and 11) harboured higher levels of genetic diversity within the indica rice than the japonica rice. An overall estimate of FST was 0·084–0·158, indicating that the differentiation is moderate and 8·4–15·8% of the total genetic variation resided between the indica and japonica groups. Our chromosome-based comparisons further suggested that the extent of the indica–japonica differentiation varied substantially, ranging from 7·62% in chromosome 3 to 28·72% in chromosome 1. Cluster analyses found that most varieties formed merely two clusters for the indica and japonica varieties, in which two japonica varieties and five indica varieties were included in the counterpart clusters, respectively. The 12 chromosome-based trees further showed that 57 rice varieties cannot be clearly clustered together into either the indica or japonica groups, but displayed relatively different clustering patterns. The results suggest that the process of indica–japonica differentiation may have proceeded through an extensive contribution by the alleles of the majority in the rice genome.

Creation and evaluation of new varieties and populations of alfalfa

2020 ◽  
Author(s):  
I. A. Meremyanina I. A. ◽  
◽  
V.V. Kenyz V.V.
Keyword(s):  
High Productivity ◽  
Green Mass ◽  
Economically Valuable Traits ◽  
New Varieties ◽  
Complex Hybrid ◽  
The Creation

The article is based on the creation and evaluation of new varieties and complex hybrid populations of alfalfa with economically valuable traits and properties.Varieties with high productivity of green mass and seeds have been created and studied.

Sign in / Sign up

Export Citation Format

Share Document