scholarly journals Selection of New Check Rice Varieties for Evaluating High Cold Tolerance and the Development of Breeding Lines with High Cold Tolerance in the Tohoku Region of Japan

2013 ◽  
Vol 47 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Koji NAKAGOMI
2021 ◽  
Author(s):  
Jimmy Lamo ◽  
David Ochan ◽  
Desta Abebe ◽  
Zelalem Zewdu Ayalew ◽  
Anna Mlaki ◽  
...  

Since introduction of rice into Uganda in 1904, improvement of the irrigated and rain-fed lowland types was undertaken to address a number of production and quality constraints in three consecutive and overlapping phases. The initial phase was achieved through evaluation of introduction, selection of promising lines and subsequent release of the selected lines for production by the farmers. In the second phase, genetic potential of traits and characteristics of interest were analyzed and used to guide selection of suitable parents for hybridization and the third phase employed genotyping approach in screening and selection of the parental lines and the segregating populations to enhance the breeding efficiency for the traits of importance. Simultaneously, the key production constraints addressed included resistance to rice yellow mottle virus (RYMV), rice blast, bacterial leaf blight and narrow leaf spot diseases as well as submergence tolerance and cold tolerance. The quality traits considered for the improvement alongside the grain yield parameters were the grain aroma, amylose content, shape and size. These interventions have resulted into release and wide adoption of seven rice varieties in Uganda besides several breeding lines which have informally diffused into different major rice production agro-ecology. Subsequently, it can be concluded that a substantially strong and functional breeding platform for rice in Uganda has been established.


2013 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
Aris Hairmansis ◽  
Bambang Kustianto ◽  
Suwarno Suwarno

<p>Development of rice varieties for tidal swamp areas is emphasized on the improvement of rice yield potential in specific environment. However, grain yield is a complex trait and highly dependent on the other agronomic characters; while information related to the relationship between agronomic characters and grain yield in the breeding program particularly for tidal swamp areas is very limited. The objective of this study was to investigate relationship between agronomic characters and grain yield of rice as a basis for selection of high yielding rice varieties for tidal swamp areas. Agronomic characters and grain yield of nine advanced rice breeding lines and two rice varieties were evaluated in a series of experiments in tidal swamp areas, Karang Agung Ulu Village, Banyuasin, South Sumatra, for four cropping seasons in dry season (DS) 2005, wet season (WS) 2005/2006, DS 2006, and DS 2007. Result from path analysis revealed that the following characters had positive direct effect on grain yield, i.e. number of productive tillers per hill (p = 0.356), number of filled grains per panicle (p = 0.544), and spikelet fertility (p = 0.215). Plant height had negative direct effect (p = -0.332) on grain yield, while maturity, number of spikelets per panicle, and 1000-grain weight showed negligible effect on rice grain yield. Present study suggests that indirect selection of high yielding tidal swamp rice can be done by selecting breeding lines which have many product tive tillers, dense filled grains, and high spikelet fertility.</p>


2013 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
Aris Hairmansis ◽  
Bambang Kustianto ◽  
Suwarno Suwarno

<p>Development of rice varieties for tidal swamp areas is emphasized on the improvement of rice yield potential in specific environment. However, grain yield is a complex trait and highly dependent on the other agronomic characters; while information related to the relationship between agronomic characters and grain yield in the breeding program particularly for tidal swamp areas is very limited. The objective of this study was to investigate relationship between agronomic characters and grain yield of rice as a basis for selection of high yielding rice varieties for tidal swamp areas. Agronomic characters and grain yield of nine advanced rice breeding lines and two rice varieties were evaluated in a series of experiments in tidal swamp areas, Karang Agung Ulu Village, Banyuasin, South Sumatra, for four cropping seasons in dry season (DS) 2005, wet season (WS) 2005/2006, DS 2006, and DS 2007. Result from path analysis revealed that the following characters had positive direct effect on grain yield, i.e. number of productive tillers per hill (p = 0.356), number of filled grains per panicle (p = 0.544), and spikelet fertility (p = 0.215). Plant height had negative direct effect (p = -0.332) on grain yield, while maturity, number of spikelets per panicle, and 1000-grain weight showed negligible effect on rice grain yield. Present study suggests that indirect selection of high yielding tidal swamp rice can be done by selecting breeding lines which have many product tive tillers, dense filled grains, and high spikelet fertility.</p>


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Luomiao Yang ◽  
Jingguo Wang ◽  
Zhenghong Han ◽  
Lei Lei ◽  
Hua Long Liu ◽  
...  

Abstract Background Cold stress caused by low temperatures is an important factor restricting rice production. Identification of cold-tolerance genes that can stably express in cold environments is crucial for molecular rice breeding. Results In this study, we employed high-throughput quantitative trait locus sequencing (QTL-seq) analyses in a 460-individual F2:3 mapping population to identify major QTL genomic regions governing cold tolerance at the seedling stage in rice. A novel major QTL (qCTS6) controlling the survival rate (SR) under low-temperature conditions of 9°C/10 days was mapped on the 2.60-Mb interval on chromosome 6. Twenty-seven single-nucleotide polymorphism (SNP) markers were designed for the qCST6 region based on re-sequencing data, and local QTL mapping was conducted using traditional linkage analysis. Eventually, we mapped qCTS6 to a 96.6-kb region containing 13 annotated genes, of which seven predicted genes contained 13 non-synonymous SNP loci. Quantitative reverse transcription PCR analysis revealed that only Os06g0719500, an OsbZIP54 transcription factor, was strongly induced by cold stress. Haplotype analysis confirmed that +376 bp (T>A) in the OsbZIP54 coding region played a key role in regulating cold tolerance in rice. Conclusion We identified OsbZIP54 as a novel regulatory gene associated with rice cold-responsive traits, with its Dongfu-104 allele showing specific cold-induction expression serving as an important molecular variation for rice improvement. This result is expected to further exploration of the genetic mechanism of rice cold tolerance at the seedling stage and improve cold tolerance in rice varieties by marker-assisted selection.


2021 ◽  
pp. 34-37
Author(s):  
Р.Х. Беков

Рассмотрены важные аспекты использования геноносителей различных маркерных признаков при создании и селекции гетерозисных гибридов томата для защищенного грунта. Наряду с общими требованиями к родительским компонентам, касающимися продуктивности растений, скороспелости, устойчивости к болезням и т. д., сегодня при селекции на гетерозис для защищенного грунта к исходному материалу предъявляют более высокие требования по наличию хозяйственно полезных признаков. Эти требования касаются типа роста растений, формы, окраски и качества плодов, типа кисти, формы плодоножки и т. д. Представлены характеристики исходного материала для создания гетерозисных гибридов томата, а также даны характеристики полученных гибридов. Исследования, проведенные в отделе селекции ВНИИО (ВНИИ овощеводства – филиал ФГБНУ ФНЦО), показали большую перспективность использования при гетерозисной селекции томата для защищенного грунта геноносителей различных маркерных признаков, особенно признаков, определяющих коричневую окраску эндосперма семян (гены bs и bs-2) и несочлененную плодоножку (ген j-2). Созданные с использованием этих маркерных признаков гибриды и селекционные линии по-своему уникальны и являются приоритетным достижением этого научного учреждения, так как они представляют большой интерес для гетерозисной селекции томата в качестве исходного материала. Целый ряд гибридов F1 включен в Госреестр селекционных достижений, допущенных к использованию (Удача, Голубчик, Клад овощевода, Заур и др.). В связи с развитием фермерского и любительского овощеводства в последние годы определенное внимание было уделено созданию новых мутантных линий с розовыми, малиновыми и темно-коричневыми плодами с высокими вкусовыми качествами (учитывая, что образцы такого типа пользуются повышенным спросом у населения и стоят дороже). При создании новых гетерозисных гибридов были учтены эти признаки родительских форм. Important aspects of the use of gene carriers of various marker traits in the creation and selection of heterotic tomato hybrids for greenhouse industry are considered. Along with the general requirements for the parent components concerning plant productivity, precocity, resistance to diseases, etc., today, when breeding for heterosis for greenhouse industry, higher requirements are imposed on the source material for the presence of economically useful features. These requirements relate to the type of plant growth, shape, colour and quality of fruits, brush type, stem shape, etc. The characteristics of the initial material for creating heterotic tomato hybrids are presented, as well as the characteristics of the resulting hybrids are given. Studies conducted in the breeding department of the ARRIVG (ARRIVG – a branch of the FSBI FSCV) showed great prospects for the use of gene carriers of various marker traits, especially those that determine the brown colour of the seed endosperm (bs and bs-2 genes) and an undifferentiated peduncle (j-2 gene) in the heterosis breeding of tomatoes for greenhouses. Hybrids and breeding lines created using these marker traits are unique in their own way and are a priority achievement of this scientific institution, since they are of great interest for the heterosis breeding of tomato as a basic material. A number of F1 hybrids are included in the State Register of Breeding Achievements allowed for use (Udacha, Golubchik, Klad ovoschevoda, Zaur, etc.). Due to the development of farming and amateur vegetable growing in recent years, some attention has been paid to the creation of new mutant lines with pink, crimson and dark brown fruits with high taste qualities (given that samples of this type are in high demand among the population and are more expensive). When creating new heterotic hybrids, these features of the parent forms were taken into account.


2021 ◽  
Author(s):  
Caijing Li ◽  
Jindong Liu ◽  
Jianxin Bian ◽  
Tao Jin ◽  
Baoli Zou ◽  
...  

Abstract Background: Rice is a crop that is very sensitive to low temperature, and its morphological development and production are greatly affected by low temperature. Therefore, understanding the genetic basis of cold tolerance in rice is of great significance for mining favorable genes and cultivating excellent rice varieties. However, there were limited studies focusing on cold tolerance at the bud burst stage, therefore, considerable attention should be paid to the genetic basis of cold tolerance at the bud burst stage (CTBB).Results: In this study, a natural population consisting of 211 rice landraces collected from 15 provinces of China and other countries were firstly used to evaluate the cold tolerance at the bud burst stage. Population structure analysis showed that this population divided into three groups and was rich in genetic diversity. Our evaluation results confered that the japonica rice was more tolerance to cold at the bud burst stage than indica rice. Genome-wide association study (GWAS) were performed through the phenotypic data of 211 rice landraces and 36,727 SNPs dataset under a mixed linear model, and 12 QTLs (P < 0.0001) were identified according to the seedling survival rate (SSR) treated at 4 ℃, in which there are five QTLs (qSSR2-2, qSSR3-1, qSSR3-2, qSSR3-3 and qSSR9) which were co-located with previous studies, and seven QTLs (qSSR2-1, qSSR3-4, qSSR3-5, qSSR3-6, qSSR3-7, qSSR4 and qSSR7) which were reported for the first time. Among these QTLs, qSSR9, harboring the highest-peak SNP, explained biggest phenotypic variation. Through bioinformatics analysis, five genes (LOC_Os09g12440, LOC_Os09g12470, LOC_Os09g12520, LOC_Os09g12580 and LOC_Os09g12720) were nominated as candidates for qSSR9. Conclusion: This natural population consisting of 211 rice landraces with high density SNPs will serve as a better choice for identifying rice QTLs/genes in future, and the detected QTLs associated with cold tolerance in rice bud burst stage will be conducive to further mining favorable genes and breeding of rice varieties under cold stress.


Author(s):  
Manjula A. C ◽  
Jenifer Lolita. C ◽  
Shubha Shubha ◽  
Prathibha K.Y ◽  
Keshamma E

We planned to conduct this study with the main aim to develop bivoltine breeds for our tropical climatic conditions by using silkworm breeds with known genetic backgrounds (KA, NB18 and PM) in various hybrid combinations and incorporating them over generations, followed by backcrossing and adequate selection of different generations with the objective of profitability and productivity. The isolated Bivoltin lines (R1 and R2) were reared with their parental races at different times of the year to evaluate their stability in the expression of commercial traits. For the present breeding program, the purebred Bivoltine Kalimpong-A (KA), which spin white oval cocoons, New Bivoltine18 (NB18) white cocoons with rotating dumbbells and Multivoltine Pure Mysore (PM), the yellow pointed cocoons of the mulberry silkworm Bombyx mori L., Selected. One-way and three-way crosses were made using the above three breeds. The first single cross comprised KA females and PM males. The second unique cross comprised NB18 females and PM males. Selection was performed at the egg, larva, pupal, and cocoon stages over the course to determine the desired traits. The offspring of F from the respective crosses were backcrossed with their respective bivoltine males to improve commercial traits. Heterosis in the F1 generations of crosses, including NB18 and PM, was determined by the mean score of the parents (MPV) and the best score of the parents (BPV). A significant test for heterosis was performed using a standard ANOVA table. Based on the results of our study, it was found that the performance of the characters, viz. The weight of mature larvae and the duration of the larvae over generations do not simply increase or decrease regularly, but fluctuate irregularly. The reason for this variation may be due to random genetic drift, sampling errors in estimating generational means, selection pressures, and environmental factors. Therefore, inbreeding variations due to random drift and sampling errors could be reduced by increasing the number sampled and selected.


2020 ◽  
Vol 23 (2) ◽  
pp. 1-15
Author(s):  
PS Biswas ◽  
H Khatun ◽  
M Anisuzzaman

Cold stress affects growth and development of rice plants from germination to reproductive stages. Thirty breeding lines/varieties including tolerant and susceptible check varieties were evaluated for cold tolerance at seedling and reproductive stage using artificially induced low temperature situations to understand the genetic relationship among them and to identify promising donors for cold tolerance. Three breeding lines, BR8253-9-3-4-3, IR77497-31-2-3-1and IR2266-42-6-2 demonstrated higher cold tolerance for the seedling stage (LD score <3.0). Molecular analysis revealed 68% genetic similarity among the genotypes. On average 64% of the breeding lines shared common alleles at any given locus ranging from 27% (RM22870) to 97% (RM186). UPGMA dendrogram showed that majority of the breeding lines showing 4-5 degrees of LD were grouped together. Two breeding lines, BR8258-7-1-5-2B2 and BR8258-7-1-5-2B3 having 86% common alleles showed low leaf discoloration (LD: 4) at seedling stage coupled with relatively low reduction in spikelet fertility (45.8% and 48.1%) and grain yield (43.3% and 39.1%). The gene diversity and PIC value revealed that seven SSR loci (RM1282, RM600, RM5349, RM6972, RM5847, RM5911, and RM511) might be the best markers to differentiate between tolerant and susceptible genotypes at reproductive stage. The breeding lines with tolerance to cold stress at the seedling and the reproductive stages identified from this study, and the SSR markers mentioned above could be useful for developing cold tolerance rice. Bangladesh Rice j. 2019, 23(2): 1-15


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4631
Author(s):  
Valtcho D. Zheljazkov ◽  
Vladimir Sikora ◽  
Ivayla Dincheva ◽  
Miroslava Kačániová ◽  
Tess Astatkie ◽  
...  

Hemp (Cannabis sativa L.) is currently one of the most controversial and promising crops. This study compared nine wild hemp (C. sativa spp. spontanea V.) accessions with 13 registered cultivars, eight breeding lines, and one cannabidiol (CBD) hemp strain belonging to C. sativa L. The first three groups had similar main essential oil (EO) constituents, but in different concentrations; the CBD hemp had a different EO profile. The concentration of the four major constituents in the industrial hemp lines and wild hemp accessions varied as follows: β-caryophyllene 11–22% and 15.4–29.6%; α-humulene 4.4–7.6% and 5.3–11.9%; caryophyllene oxide 8.6–13.7% and 0.2–31.2%; and humulene epoxide 2, 2.3–5.6% and 1.2–9.5%, respectively. The concentration of CBD in the EO of wild hemp varied from 6.9 to 52.4% of the total oil while CBD in the EO of the registered cultivars varied from 7.1 to 25%; CBD in the EO of the breeding lines and in the CBD strain varied from 6.4 to 25% and 7.4 to 8.8%, respectively. The concentrations of δ9-tetrahydrocannabinol (THC) in the EO of the three groups of hemp were significantly different, with the highest concentration being 3.5%. The EO of wild hemp had greater antimicrobial activity compared with the EO of registered cultivars. This is the first report to show that significant amounts of CBD could be accumulated in the EO of wild and registered cultivars of hemp following hydro-distillation. The amount of CBD in the EO can be greater than that in the EO of the USA strain used for commercial production of CBD. Furthermore, this is among the first reports that show greater antimicrobial activity of the EO of wild hemp vs. the EO of registered cultivars. The results suggest that wild hemp may offer an excellent opportunity for future breeding and the selection of cultivars with a desirable composition of the EO and possibly CBD-rich EO production.


2016 ◽  
Vol 15 (2) ◽  
pp. 127-137
Author(s):  
Kuyyamudi Nanaiah Ganapathy ◽  
Sujay Rakshit ◽  
Sunil Shriram Gomashe ◽  
Suri Audilakshmi ◽  
Krishna Hariprasanna ◽  
...  

Knowledge on genetic diversity is necessary to determine the relationships among the genotypes, which allow the selection of individual accessions for crop breeding programmes. The present study aimed at assessing the extent and pattern of genetic diversity within a set of 251 sorghum genotypes using SSR markers. A total of 393 alleles were detected from the 251 genotypes, with the number of alleles ranging from 2 (Xcup11) to 24 (Sb5-206) and an average of 10.07 alleles per primer pair. Pairwise Wright's FST statistic and Nei's genetic distance estimates revealed that the race and geographical origin were responsible for the pattern of diversity and structure in the genetic materials. In addition, the analysis also revealed high genetic differentiation between the rainy and post-rainy sorghum groups. Narrow diversity was observed among the different working groups in the rainy (restorers and varieties) and post-rainy (varieties and advanced breeding lines) sorghum groups. Neighbour-joining and STRUCTURE analysis also classified 44 elite lines broadly into two distinct groups (rainy and post-rainy). However, limited diversity within the rainy and post-rainy sorghum groups warranted an urgent need for the utilization of diverse germplasm accessions for broadening the genetic base of the Indian breeding programme. The diverse germplasm accessions identified from the mini-core accessions for utilization in breeding programmes are discussed.


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