scholarly journals Mapping of QTLs for source and sink associated traits under elevated CO2 in rice (Oryza sativa L.)

2019 ◽  
Vol 90 (2) ◽  
pp. 359-367
Author(s):  
Li-Ping Dai ◽  
Xue-Li Lu ◽  
Wei-Wei Zou ◽  
Chang-Jian Wang ◽  
Lan Shen ◽  
...  

AbstractRice source- and sink-associated traits are important for grain yield and are sensitive to environmental conditions. The continuing increase of CO2 concentrations in the atmosphere will become a major challenge for rice growth and development in the future due to changes in our climate such as extremes in temperature. To guarantee food safety, novel genetic loci need to be identified for source- and sink-associated traits that are specifically expressed under elevated CO2 conditions. Eighty chromosome segment substitution lines carrying japonica (Nipponbare) chromosome segments in the indica (9311) background were used in this study. QTL analysis was conducted for source- and sink-related traits, including flag leaf length, flag leaf width, flag leaf fresh weight, flag leaf dry weight, primary branch number, secondary branch number, grain number per panicle, panicle weight per plant, chlorophyll a, chlorophyll b, and carotenoid contents, under ambient CO2 concentrations and free-air CO2 enrichment. A total of 49 QTLs for these traits were detected on chromosomes 1, 3, 5, 6, 7, 9, and 12 under the two conditions; the variance explained by these QTLs varied from 6.22 to 38.15%. Among these QTLs, 19 of them were detected under the natural field conditions and 30 were detected in the elevated CO2 conditions. In addition, 2 and 13 QTLs were specifically expressed in the natural and CO2-enriched conditions, respectively. Our findings have important implications on the utilization of germplasm resources for ensuring food security under elevated CO2 levels, especially for QTLs that were specifically detected under the elevated CO2 condition.

2020 ◽  
Vol 21 (4) ◽  
pp. 1344 ◽  
Author(s):  
Shaowen Yuan ◽  
Yuntong Wang ◽  
Chaopu Zhang ◽  
Hanzi He ◽  
Sibin Yu

Timing of germination determines whether a new plant life cycle can be initiated; therefore, appropriate dormancy and rapid germination under diverse environmental conditions are the most important features for a seed. However, the genetic architecture of seed dormancy and germination behavior remains largely elusive. In the present study, a linkage analysis for seed dormancy and germination behavior was conducted using a set of 146 chromosome segment substitution lines (CSSLs), of which each carries a single or a few chromosomal segments of Nipponbare (NIP) in the background of Zhenshan 97 (ZS97). A total of 36 quantitative trait loci (QTLs) for six germination parameters were identified. Among them, qDOM3.1 was validated as a major QTL for seed dormancy in a segregation population derived from the qDOM3.1 near-isogenic line, and further delimited into a genomic region of 90 kb on chromosome 3. Based on genetic analysis and gene expression profiles, the candidate genes were restricted to eight genes, of which four were responsive to the addition of abscisic acid (ABA). Among them, LOC_Os03g01540 was involved in the ABA signaling pathway to regulate seed dormancy. The results will facilitate cloning the major QTLs and understanding the genetic architecture for seed dormancy and germination in rice and other crops.


2016 ◽  
Vol 103 ◽  
pp. 96-105 ◽  
Author(s):  
Noppawan Nounjan ◽  
Jonaliza L. Siangliw ◽  
Theerayut Toojinda ◽  
Supachitra Chadchawan ◽  
Piyada Theerakulpisut

Weed Science ◽  
1986 ◽  
Vol 34 (5) ◽  
pp. 704-710 ◽  
Author(s):  
Tim R. Murphy ◽  
Billy J. Gossett ◽  
Joe E. Toler

A comparative study of the growth and development of several populations of dinitroaniline-susceptible (DS) and -resistant (DR) goosegrass [Eleusine indica(L.) Gaertn. # ELEIN] biotypes was conducted under noncompetitive field conditions. Plant height and width, number of tillers, aboveground dry weight, relative growth rate (RGR), number of inflorescences/plant, total inflorescence dry weight, individual inflorescence dry weight, number of spicate branches/inflorescence, and flag leaf length and width were recorded periodically during the growing season. There were no significant differences between biotypes in most characteristics with the exception of total inflorescence dry weight. The DS biotype produced more total inflorescence dry weight than the DR biotype at 8 and 13 weeks after transplanting. Significant variation among DS and DR populations occurred in 37 and 33 of 56 evaluations, respectively. When variation existed within a biotype, populations exhibited broad ranges of response for the various growth parameters. With the exception of total inflorescence dry weight, DS and DR biotypes generally exhibited similar ranges of variability.


2020 ◽  
Vol 12 (3) ◽  
pp. 292-298
Author(s):  
Amod Kumar ◽  
Shiv Kumar ◽  
Sarvendra Singh ◽  
Janeshwar Prasad ◽  
A. S. Jeena ◽  
...  

Rice is most important food crop of India and grown in different regions with differential consumer preferences for grain size, shape, aroma and cooking qualities. Therefore, crop improvement in rice not only focused on yield but also to enhance quality. Hence the present investigation was carried out with an objective of assessing the character association among twenty-two morphological and quality characters of thirty basmati rice (Oryza sativa L) genotypes. Correlation analysis revealed that Seed yield was significantly and positively associated with days to maturity (0.330**), number of tillers per plant (0.434**), number of grains per panicle (0.358**), grain weight per panicle (0.410**), and flag leaf length (0.258*).  The days to maturity exhibited a significant positive correlation with plant height, panicle length, grain weight per plant, kernel length before cooking, kernel length after cooking and L: B ratio. Tiller per plant reflected the positive and significant association with a number of grains per panicle, grain weight per panicle and grain weight per plant. Flag leaf length showed a significant positive correlation with a number of grains per panicle and grain weight per plant, while Grains per panicle was positively and significantly associated with grain weight per panicle, grain weight per plant and kernel breadth before cooking.  Grain weight per panicle exhibited a significant positive association with grain yield per plant (0.410**), kernel breadth before cooking (0.381**), 100 grain weight (0.240*) and 100 kernel weight (0.210*).  These characters could be utilized to form a selection index for improvement of the basmati rice.


Author(s):  
D.R. Meghawal ◽  
G.M. Lal ◽  
Ranjana Tiwari

The present investigation consists of 34 genotypes with one local check (NDR-359) grown at field experimentation centre at the Department of Genetic and Plant Breeding, SHIATS, Allahabad evaluated for thirteen quantitative characters. All the genotypes differed significantly with respect to all the quantitative traits. High to moderate estimates of GCV and PCV were found for number of panicle per plant, number of tiller per plant, plant height and number of spikelet’s per panicle, indicating these traits could be use for selection in crop improvement. Plant height, number of spikelet’s per panicle, test weight and flag leaf length exhibited high values for broad sense heritability. Number of spikelet’s and plant height showed highest genetic advance coupled with high heritability, which is also exhibited by number of panicle per plant, number of tillers per plant and plant height suggesting pre dominance of additive gene action in the expression of these traits.


Genome ◽  
2010 ◽  
Vol 53 (10) ◽  
pp. 763-768 ◽  
Author(s):  
Natsuko Iwata ◽  
Kenji Fujino

The effects of QTLs are demonstrated basically within the population used in the original QTL analysis as the difference between the alleles of the parental varieties. For the efficient use of QTLs in breeding programs, it is necessary to assess whether the QTL exhibits its genetic effect when it is introgressed into different genetic backgrounds. Extensive studies of tolerance to low temperature at the seed germination stage (called low-temperature germinability) in rice revealed that 2 major QTLs on chromosomes 3 and 11, qLTG3-1 and qLTG11, have large effects. This study assessed the effects of these 2 QTLs from an aus variety, Kasalath, in different genetic backgrounds of 3 japonica varieties, Hoshinoyume, Hayamasari, and Koshihikari. Backcrossed progenies and chromosome segment substitution lines showed that both qLTG3-1 and qLTG11 were effective in the Hoshinoyume and Koshihikari backgrounds, while only qLTG3-1 was effective in the Hayamasari background. The results in this study demonstrated that these 2 QTLs are useful for the improvement of low-temperature germinability in rice breeding programs. The results also indicated that low-temperature germinability in rice is governed by an epistatic interaction of qLTG11.


2013 ◽  
Vol 26 (1) ◽  
pp. 19-24 ◽  
Author(s):  
M. A. Siddique ◽  
M. Khalequzzaman ◽  
M. Z. Islam ◽  
M. S. Ahamed ◽  
E. S. M. H. Rashid

Genetic diversity in 40 traditional boro rice genotypes was studied under irrigated condition through Mahalanobis D2 statistic for grain yield and yield contributing characters. The genotypes were grouped into five clusters. The inter-cluster distances were higher than intra-cluster distances indicating wider genetic diversity among the clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the genotypes within the clusters. The cluster IV contained the highest number of genotypes (22) and the cluster II and V contained the lowest (1). The highest intra-cluster distance was noticed for the cluster III and lowest for cluster II and V. The highest inter-cluster distance was observed between cluster II and III followed by cluster II and V, cluster I and II and the lowest between cluster I and IV. Regarding inter-cluster distance, the genotypes of cluster II   showed high genetic distance from all other clusters. The genotypes from cluster II could be hybridized with the genotypes of other clusters for producing transgressive segregants. Based on positive value of vector 1 and vector 2, panicle/hill had maximum contribution towards genetic divergence. The highest cluster means for yield, flag leaf length and grain length breadth ratio were obtained from cluster IV. The highest 1000-grain weight, shortest growth duration and grain breadth were found in cluster II while the lowest mean value for yield, flag leaf length, filled grains and 1000 grain weight were found in cluster V.  Therefore, more emphasis should be given on cluster II, III and cluster IV for selecting genotypes as parents for crossing with the genotypes of cluster V which would be used to produce new recombinants with desired traits.DOI: http://dx.doi.org/10.3329/bjpbg.v26i1.19980


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