rice varieties
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2023 ◽  
Vol 83 ◽  
Author(s):  
A. Younas ◽  
W. Xiukang ◽  
Z. Yousaf ◽  
S. Fiaz ◽  
A. Riaz ◽  
...  

Abstract A huge amount of rice cultivation and consumption occur in Asia particularly in Pakistan and China. However, multiple abiotic stresses especially high and low-temperature proved to be a substantial threat for rice production ultimately risks for food security. To overcome various types of abiotic stress; seed priming is among the effective approaches to improve the rice seed germination and growth vigor. Therefore, the present study was planned to evaluate physiological and biochemical modifications in Chinese and Pakistani rice varieties by Qiangdi 863 biological assistant growth apparatus nano treated water (NTW), Osmopriming Calcium chloride (CaCl2), redox priming hydrogen peroxide (H2O2) and hormonal priming by Salicylic acid (SA) under temperature stress conditions. The experiment was performed with completely randomize design conditions. Five rice varieties, nomenclature as Zhongzoa 39, (Chinese rice variety) KSK 133, KS 282, Super basmati and PK 1121 aromatic (Pakistani rice variety) were sown under low temperature (LT) (17ºC), optimal temperature (OT) 27ºC and high temperature (HT) 37ºC conditions. The present study indicated that nanopriming were the most effective treatments increased Germination Energy Percentage (GEP) (96.1, 100, 100%), Speed of Germination (SG) (27.2, 35.45, 37.1), Final Germination Percentage (FGP) (98.2, 99.1, 99.4%), Seedling Dry Weight Biomass (DWB) (0.1, 0.137, 0.14g), Total Chlorophyll Content (0.502, 13.74, 15.21), antioxidant enzymes Superoxide Dismutase (SOD)(3145, 2559, 3345 µg-1FWh-1), Catalase (CAT) (300, 366, 3243 µg-1FWh-1) and decreased Malondialdehyde (MDA) (6.5, 12.2, 6.5 µmol g-1 FW) for Zhongzao 39 and KSK 133 rice varieties under low (LT+NTW), optimal temperature (OP+NTW) and high temperature (HT+NTW) stress., Therefore, nano-priming is recommended to cope with the high and low-temperature stress conditions along with improved productivity of rice.


2024 ◽  
Vol 84 ◽  
Author(s):  
S. N. Yazid ◽  
K. Ahmad ◽  
M. S. F. A. Razak ◽  
Z. A. Rahman ◽  
K. Ramachandran ◽  
...  

Abstract Bacterial leaf blight (BLB) is one of the major rice diseases in Malaysia. This disease causes substantial yield loss as high as 70%. Development of rice varieties which inherited BLB resistant traits is a crucial approach to promote and sustain rice industry in Malaysia. Hence, this study aims were to enhance BLB disease resistant characters of high yielding commercial variety MR219 through backcross breeding approach with supporting tool of marker-assisted selection (MAS). Broad spectrum BLB resistance gene, Xa7 from donor parent IRBB7 were introgressed into the susceptible MR219 (recurrent parent) using two flanking markers ID7 and ID15. At BC3F4, we managed to generate 19 introgressed lines with homozygous Xa7 gene and showed resistant characteristics as donor parent when it was challenged with Xanthomonas oryzae pv. oryzae through artificial inoculation. Recurrent parent MR219 and control variety, MR263 were found to be severely infected by the disease. The improved lines exhibited similar morphological and yield performance characters as to the elite variety, MR219. Two lines, PB-2-107 and PB-2-34 were chosen to be potential lines because of their outstanding performances compared to parent, MR219. This study demonstrates a success story of MAS application in development of improved disease resistance lines of rice against BLB disease.


Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 85
Author(s):  
Chengling Lai ◽  
Yun Hou ◽  
Peiying Hao ◽  
Kun Pang ◽  
Xiaoping Yu

The brown planthopper (BPH), Nilaparvata lugens, is a serious pest of rice throughout Asia. Yeast-like symbionts (YLS) are endosymbionts closely linked with the development of BPH and the adapted mechanism of BPH virulence to resistant plants. In this study, we used semi-quantitative DGGE and absolute quantitative real-time PCR (qPCR) to quantify the number of the three YLS strains (Ascomycetes symbionts, Pichia-like symbionts, and Candida-like symbionts) that typically infect BPH in the nymphal stages and in newly emerged female adults. The quantities of each of the three YLS assessed increased in tandem with the developing nymphal instar stages, peaking at the fourth instar stage, and then declined significantly at the fifth instar stage. However, the amount of YLS present recovered sharply within the emerging adult females. Additionally, we estimated the quantities of YLS for up to eight generations after their inoculation onto resistant cultivars (Mudgo, ASD7, and RH) to reassociate the dynamics of YLS with the fitness of BPH. The minimum number of each YLS was detected in the second generation and gradually increased from the third generation with regard to resistant rice varieties. In addition, the Ascomycetes symbionts of YLS were found to be the most abundant of the three YLS strains tested for all of the development stages of BPH.


2022 ◽  
Vol 31 (2) ◽  
pp. 115-122
Author(s):  
Rita Sarah Borna ◽  
S Mitra ◽  
AJA Gifary ◽  
RH Sarker

Biramsundari is a rice germplasm from Bangladesh showing one to four grain in a single seed. Comparative study of morphological traits revealed that BS is a taller rice variety compared to modern rice varieties with longer and wider flag leaves, longer panicle length and higher thousand seed weight (TSW) than transplanted aman rice variety BRRI dhan 49. Flower morphological analysis unveil that multiple grains of Biramsundari are originating from multiple number of carpels in each floret. About 40.1% flower contains three carpels. Fluorescent microscopic study also confirms the zygotic origin of multiple grain formation in Biramsundari. Molecular characterisation of Biramsundari was performed by using TeaCpSSR27 and TeaCpSSR28 chloroplast microsatellite markers. The results of this investigation reveal that atpF and rsp14-psaB intergenic spacer regions of Biramsundari have variation compared to sequences of with O. sativa ssp. indica, O. sativa ssp. japonica and O. rufipogon. Plant Tissue Cult. & Biotech. 31(2): 115-122, 2021 (December)


2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Xiong Yuan ◽  
Zirong Li ◽  
Liwen Xiong ◽  
Sufeng Song ◽  
Xingfei Zheng ◽  
...  

Abstract Background Plant variety identification is the one most important of agricultural systems. Development of DNA marker profiles of released varieties to compare with candidate variety or future variety is required. However, strictly speaking, scientists did not use most existing variety identification techniques for “identification” but for “distinction of a limited number of cultivars,” of which generalization ability always not be well estimated. Because many varieties have similar genetic backgrounds, even some essentially derived varieties (EDVs) are involved, which brings difficulties for identification and breeding progress. A fast, accurate variety identification method, which also has good performance on EDV determination, needs to be developed. Results In this study, with the strategy of “Divide and Conquer,” a variety identification method Conditional Random Selection (CRS) method based on SNP of the whole genome of 3024 rice varieties was developed and be applied in essentially derived variety (EDV) identification of rice. CRS is a fast, efficient, and automated variety identification method. Meanwhile, in practical, with the optimal threshold of identity score searched in this study, the set of SNP (including 390 SNPs) showed optimal performance on EDV and non-EDV identification in two independent testing datasets. Conclusion This approach first selected a minimal set of SNPs to discriminate non-EDVs in the 3000 Rice Genome Project, then united several simplified SNP sets to improve its generalization ability for EDV and non-EDV identification in testing datasets. The results suggested that the CRS method outperformed traditional feature selection methods. Furthermore, it provides a new way to screen out core SNP loci from the whole genome for DNA fingerprinting of crop varieties and be useful for crop breeding.


Author(s):  
Jennifer T. Niones ◽  
Ryan T. Sharp ◽  
Dindo King M. Donayre ◽  
Eula Gems M. Oreiro ◽  
Alice E. Milne ◽  
...  

AbstractBacterial blight (X. oryzae pv. oryzae) is a serious disease in rice across the world. To better control the disease, it is important to understand its epidemiology and how key aspects of this (e.g. infection efficiency, and spatial spread) change according to environment (e.g. local site conditions and season), management, and in particular, variety resistance. To explore this, we analysed data on the disease progress on resistant and susceptible varieties of rice grown at four sites in the Philippines across five seasons using a combination of mechanistic modelling and statistical analysis. Disease incidence was generally lower in the resistant variety. However, we found no evidence that the primary infection efficiency was lower in resistant varieties, suggesting that differences were largely due to reduced secondary spread. Despite secondary spread being attributed to splash dispersal which is exacerbated by wind and rain, the wetter sites of Pila and Victoria in south Luzon tended to have lower infection rates than the drier sites in central Luzon. Likewise, we found spread in the dry season can be substantial and should therefore not be ignored. In fact, we found site to be a greater determinant of the number of infection attempts suggesting that other environmental and management factors had greater effect on the disease than climate. Primary infection was characterised by spatially-random observations of disease incidence. As the season progressed, we observed an emerging short-range (1.6 m–4 m) spatial structure suggesting secondary spread was predominantly short-range, particularly where the resistant variety was grown.


Discover Food ◽  
2022 ◽  
Vol 2 (1) ◽  
Author(s):  
Min Huang ◽  
Zhengwu Xiao ◽  
Liqin Hu ◽  
Jiana Chen ◽  
Fangbo Cao

AbstractThe amylose content of newly-released rice varieties has steadily decreased in rice-growing regions in the middle reach of the Yangtze River during 2006–2021, to parallel increasing consumption of soft-textured rice with low amylose content. We estimated the glycemic index of these newly-released rice varieties and reveal a significantly increasing trend, showing a 0.3 annual increase in estimated glycemic index of new rice varieties released each year. These results highlight the need to assess the potential health risks associated with the development of soft-textured rice with low amylose rice.


Plants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 132
Author(s):  
Wei Wang ◽  
Qiang Tu ◽  
Rongrong Chen ◽  
Pincang Lv ◽  
Yanqing Xu ◽  
...  

Plant polyploidization is frequently associated with changes in nutrient contents. However, the possible contribution of metabolites to this change has not been investigated by characterizing the metabolite contents of diploid and tetraploid forms of rice (Oryza sativa L.). We compared the metabolites of a group of diploid–tetraploid japonica brown rice and a group of diploid–tetraploid indica brown rice based on liquid chromatography–tandem mass spectrometry. In total, 401 metabolites were identified; of these, between the two diploid–tetraploid groups, 180 showed opposite expression trends, but 221 showed the same trends (147 higher abundance vs. 74 lower abundance). Hierarchical cluster analysis of differential metabolites between diploid and tetraploid species showed a clear grouping pattern, in which the expression abundance of lipids, amino acids and derivatives, and phenolic acids increased in tetraploids. Further analysis revealed that the lipids in tetraploid rice increased significantly, especially unsaturated fatty acids and phospholipids. This study provides further basis for understanding the changes in rice nutritional quality following polyploidization and may serve as a new theoretical reference for breeding eutrophic or functional rice varieties via polyploidization.


Agriculture ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Yunji Shin ◽  
Yong Jae Won ◽  
Chaewon Lee ◽  
Kyeong-Seong Cheon ◽  
Hyoja Oh ◽  
...  

Grain size is a key factor influencing the grain yield in rice. To identify the as-yet-unknown genes regulating grain size in Korean japonica rice, we developed a recombinant inbred line population (n = 162) from a cross between Odae (large-grain) and Joun (small-grain), and measured six traits including the thousand-grain weights of unhulled and hulled seeds, grain area, grain length, grain width and grain length-to-width ratio using high-throughput image analysis at the F8 and F9 generations. A genetic map was constructed using 248 kompetitive allele-specific PCR (KASP) markers that were polymorphic between the parental genotypes, and 29 QTLs affecting the six traits were identified, of which 15 were stable in both F8 and F9 generations. Notably, three QTL clusters affecting multiple traits were detected on chromosomes 6, 7 and 11. We analyzed whole-genome resequencing data of Odae and Joun, and selected candidate genes for the stable QTLs in the identified clusters that have high- or moderate-impact variations between Odae and Joun and encode proteins the families of which have been reported to be related to grain size regulation. These results will facilitate the identification of genes underlying the QTLs and promote molecular breeding of high-yielding Korean japonica rice varieties.


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