首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7篇
  免费   1篇
农学   2篇
  1篇
农作物   3篇
水产渔业   2篇
  2022年   1篇
  2021年   1篇
  2019年   1篇
  2018年   1篇
  2017年   2篇
  2013年   2篇
排序方式: 共有8条查询结果,搜索用时 46 毫秒
1
1.
Identification of new parental lines is crucial for developing ecology‐specific hybrids with ideal agronomic performance. We screened a total of 570 different ecology‐specific Indian rice varieties for the presence of fertility restorer genes, Rf3 and Rf4 using tightly linked markers DRRM Rf3‐10 and RM6100, respectively. Among these varieties, 13% carried Rf3Rf3/Rf4Rf4, 31% carried rf3rf3/rf4rf4, 6% carried Rf3Rf3/rf4rf4 and remaining 50% carried Rf4Rf4/rf3rf3 allelic combinations. A mini set of 40 varieties with variable allelic combinations of fertility restorer genes were testcrossed with WA and Kalinga‐based CMS lines. All the 80 F1s were evaluated for spikelet fertility and fertility restoration ability. Rf3Rf3/rf4rf4 genotypes mostly behaved as partial maintainers or partial restorers. In contrast, rf3rf3/Rf4Rf4 genotypes were partial or effective restorers. However, double dominant genotypes showed better fertility restoration than the genotypes containing Rf3 or Rf4 individually. Some of the genotypes showed unexpected restoration pattern implying occurrence of other fertility restorer(s) apart from Rf3 and Rf4. The perfect restorers and maintainers identified in this study can be directly used in hybrid rice breeding.  相似文献   
2.
The introgression of wild chromosomal segments into popular rice varieties is one of the potential approaches for developing varieties for drought stress condition. Sixteen genotypes, including nine indica, two tropical japonica and five chromosome segments substitution lines(CSSLs) with different levels of tolerance/susceptibility to drought stress, were selected for diversity study. Sixty-three microsatellite markers were utilized for assessing genetic diversity. A total of 95 alleles were amplified, and out of them, 60 were polymorphic. Six unique alleles, amplified by the microsatellite loci RM276, RM472,RM488, RM537, RM541 and RM28089, were identified in six genotypes, namely FR13A, Brahamanakhi,RUF44, Swarna-sub1, Brahamanakhi and Satyabhama. The highest genetic similarity was found among CSSLs. Polymorphism information content(PIC) value varied from 0 to 1.00 with an average of 0.66 per locus. Twenty-eight microsatellites were found to be polymorphic, which could be used in marker-assisted selection programme. All the sixteen genotypes were grouped into two major clusters at genetic similarity of 0.64. In the cluster I, five CSSLs identified as diverse genotypes had wild ancestor segments responsible for drought tolerance, and hence they could be utilized as potential donors. The popular Indian varieties, Swarna-sub1 and IR64-sub1, could be used as recurrent parents in the future breeding program for developing varieties for abiotic stresses such as submergence and drought.  相似文献   
3.
A nutrient budget was quantified for six polyculture ponds of giant freshwater prawn (Macrobrachium rosenbergii) and Indian major carps (Catla catla, Labeo rohita, and Cirrhinus mrigala). The initial stocking size of prawn postlarva was 16.50 ± 0.54 mm with a body weight of 0.05 ± 0.001 g. Body weight of major carps was 9.0 ± 0.89 g. The duration of culture was 280 days. Feed accounted for 82% of total nitrogen (N), 93% of total phosphorus (P), and 95% of organic carbon (OC) inputs. Harvest of prawn and carps recovered 44% N, 1% P, and 19% OC. N, P, and OC accumulated in sediment were 47%, 73%, and 69%, respectively. Nutrient load in the harvest water was 0.67 ± 0.21 kg inorganic N, 0.15 ± 0.01 kg P, and 7.72 ± 0.62 kg OC per ton of Indian major carps and prawn.  相似文献   
4.
Nutrient budget for shrimp (Penaeus monodon) culture was performed in ten culture ponds (0.4–1.0 ha) in Orissa, India, at stocking density of 10.0–22.10/m2. The average initial body weight of shrimps was 0.02 g. The culture period was for 4 months. Feed was the main input of nitrogen (N), phosphorus (P) and organic carbon (OC). The FCR varied from 1.35 to 1.75. At harvest time, the average weight of shrimps varied from 28 to 32 g. Total N, P and OC applied to these ponds through all the inputs ranged from 106.64 to 292.63, 23.17 to 57.55 kg and 763.10 to 1,831.20 kg per crop, respectively. Feed alone accounted for 94.43–95.03 % total N, 91.92–95.36 % total P and 80.33–92.48 % total OC, respectively. The harvest of shrimp accounted for recovery of 25.45–36.88 (av. 30.12) %, 10.07–12.94 (av. 11.16) % and 15.80–20.81 (av. 18.01) % of added N, P and OC, respectively. N, P and OC accumulated in sediment were 49.11, 64.07 and 64.82 %, respectively, of total nutrient retention in the culture system. Unaccounted N, P and OC were 13.29, 21.83 and 18.14 %, respectively, of the total nutrient retention in the system. N, P and OC outputs in the discharged water during harvest were 7.48, 2.94 and 2.03 %, respectively.  相似文献   
5.
The brown planthopper (BPH) is a potent pest of rice in Asia and Southeast Asia. Host resistance has been found to be the most suitable alternative to manage the insect. But varietal resistance has been found to be short-lived. There has been a constant search for alternate resistance genes. We developed an F8 recombinant inbred population for the BPH resistance gene in Salkathi, an indica landrace from Odisha, India. Phenotyping of RILs against the BPH population at Cuttack, Odisha showed continuous skewed variation with four peaks at 2.1–3.0, 4.1–5.0, 6.1–7.0 and 8.1–9.0 SES score, suggesting the involvement of quantitative loci for resistance to BPH in Salkathi. Mapping showed the presence of two QTLs on the short arm of chromosome 4. One QTL, with phenotype variance of 37.02% is located between the markers RM551 and RM335. The other QTL, with phenotype variance of 7.1% is located between markers RM335 and RM5633. The two QTLs have been designated as qBph4.3 and qBph4.4. QBph4.3 seems to be a novel QTL associated with BPH resistance. We have successfully transferred qBph4.3 and qBph4.4 into two elite rice cultivars, Pusa 44 and Samba Mahsuri. Fine mapping of the identified QTLs may lead to a successful transfer of QTLs into other elite germplasm backgrounds.  相似文献   
6.
Genetic Resources and Crop Evolution - Rice varieties are generally bred for higher yield but may possess genomic regions conferring tolerance to abiotic stresses. Climate change driven heat stress...  相似文献   
7.
Grain size plays a significant role in rice, starting from affecting yield to consumer preference, which is the driving force for deep investigation and improvement of grain size characters. Quantitative inheritance makes these traits complex to breed on account of several alleles contributing to the complete trait expression. We employed genome-wide association study in an association panel of 88 rice genotypes using 142 new candidate gene based SSR (cgSSR) markers, derived from yield-related candidate genes, with the efficient mixed-model association coupled mixed linear model for dissecting complete genetic control of grain size traits. A total of 10 significant associations were identified for four grain size-related characters (grain weight, grain length, grain width, and length-width ratio). Among the identified associations, seven marker trait associations explain more than 10% of the phenotypic variation, indicating major putative QTLs for respective traits. The allelic variations at genes OsBC1L4, SHO1 and OsD2 showed association between 1000-grain weight and grain width, 1000-grain weight and grain length, and grain width and length-width ratio, respectively. The cgSSR markers, associated with corresponding traits, can be utilized for direct allelic selection, while other significantly associated cgSSRs may be utilized for allelic accumulation in the breeding programs or grain size improvement. The new cgSSR markers associated with grain size related characters have a significant impact on practical plant breeding to increase the number of causative alleles for these traits through marker aided rice breeding programs.  相似文献   
8.
A total of 17 simple sequence repeat (SSR) markers linked to QTLs (qDTYs) governing grain yield under reproductive stage (RS) drought stress were used to assess the genetic relationship and prospecting new donors for qDTYs among 32 popular upland rice genotypes. These SSR markers generated a total of 36 alleles with an average allele count of 2.1 per locus. Polymorphic information content value of the markers ranged from 0.376 to 0.662 with an average value of 0.484. The expected heterozyogosity ranged from 0.381 to 0.632. STRUCTURE analysis divided the 32 genotypes into three sub-populations. Subsequent phenotyping revealed that all the tolerant genotypes were grouped into one sub-population, whereas the moderately tolerant and susceptible genotypes were grouped into separate sub-populations. Phylogenetic tree constructed by the unweighted neighbour-joining method also divided the genotypes into three clusters. The grouping pattern of genotypes into the clusters was similar to that into the STRUCTURE analysis, on the basis of drought tolerance level. The average value of genetic dissimilarity coefficient among the genotypes was observed to be 0.486. Furthermore, by combining genotyping data with phenotyping data, 16 new donors for 6 qDTYs were identified.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号