Enhancing Seed Yield of Hybrid Rice by Maintaining Row Ratio and Dosages of Gibberellic Acid

Abstract The purpose of this study was to identify the optimum levels of gibberellic acid and suitable row ratio for maximization the seed yield of hybrid rice. An experiment was conducted at the experimental farm of Rice Research and Training Center, Egypt, during 2013 and 2014 growing seasons. The material under this study included the parental lines of IR69625A (Female lines) and Giza 179 R (Restorer line) to produce F0 hybrid seeds. A split-plot design with three replications was used. The main plot was row ratio (2R:8A, 2R:10A and 2R:12A) and sub plots was the doses of gibberellic acid (g/ha) (control, 300, 350, 400). The results indicated that, Application of GA3 and row ratio had significant effect on different traits of seed yield and hybrid seed production. The highest values of flag leaf area, panicle length, seed set, panicle weight, panicle exsertion and seed yield were acheived by using 2R: 8A row ratio and was observed the lowest values were obtained at the 2:12 row ratio. Acoording to gibberellic acid application, the highest values for panicle length (cm), seed set (%), panicle weight (g), panicle exertion (%), harvest index and seed yield were recorded by using 400 g /ha gibberellic acid. Accordingly, the highest net economic return from seed yield was obtained with the treatment combination of 400 g/ha GA3 x 2:8 (R: A) row ratio.

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Flowering Synchronization in Hybrid Rice Parental Lines at Different Sowing Dates

Sustainability ◽

10.3390/su13063229 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3229

Author(s):

Mahmoud Gaballah ◽

Hassan Hamad ◽

Atif Bamagoos ◽

Hesham Alharby ◽

Sharif Ahmed ◽

...

Keyword(s):

Plant Height ◽

Seed Yield ◽

Harvest Index ◽

Field Experiments ◽

Seed Set ◽

Hybrid Rice ◽

Research Station ◽

Panicle Length ◽

Sowing Dates ◽

Panicle Weight

Hybrid seed set on the female line depends primarily on its flowering synchronization with the restorer line (R), therefore, the sowing of male and female lines must be planned properly to achieve this. Field experiments on different sowing dates (May 1st, May 15th, and May 30th) of R lines (Giza 178R, Giza 179R, and Giza 181R) and cytoplasmic male sterile (CMS) lines (IR69625A, IR70368A, IR58025A, K17A, and G46A) were carried out at the farm of Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt during 2019 and 2020 to study the effect of sowing dates on flowering synchronization in hybrid rice. The results indicated that the synchronization of flowering between CMS lines and R lines has highly significant effects on the days to 50% heading, number of leaves, effective accumulated temperature (EAT), plant height, panicle exertion percentage, panicle length, number of fertile panicles, panicle weight, seed set percentage, harvest index and seed yield of hybrid rice. The highest seed yield (1.72 and 1.41 t ha−1, respectively in 2019 and 2020) was recorded from the sowing date May 1st and the hybrid combination of Giza 178R × IR58025A (2.06 and 2.12 t ha−1 in 2019 and 2020, respectively). The grain yield had a significant and highly significant positive correlation with the plant height (cm), panicle exertion percentage, panicle length, number of panicles plant−1, panicle weight, seed set percentage, and harvest index. In Egypt, May 1st is the best time for the synchronization of hybrid rice lines and a combination of Giza 178R × IR58025A may be recommended for better performance.

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Detection of QTLs for Outcrossing-Related Traits in CSSL Population Derived from Primitive Japonica Accession Ludao in the Genetic Background of O. sativa spp. Japonica Restorer C-bao Using RSTEP-LRT Method

Agronomy ◽

10.3390/agronomy10010028 ◽

2019 ◽

Vol 10 (1) ◽

pp. 28

Author(s):

Lal Bux ◽

Dalu Li ◽

Muhammad Faheem ◽

Nour Ali ◽

Muzafar Hussain Sirohi ◽

...

Keyword(s):

Seed Production ◽

Hybrid Rice ◽

Oryza Sativa L ◽

Flag Leaf ◽

Leaf Angle ◽

Ratio Test ◽

Phenotypic Variance ◽

Rice Seed ◽

Hybrid Seed Production ◽

Cms Line

The outcrossing traits in rice (Oryza sativa L.) affect the yield of hybrid seed production. Using a cytoplasmic male sterile (CMS) line with good outcrossing traits, such as short flag leaf length (FLL), narrow flag leaf width (FLW), wide flag leaf angle (FLA), and elongated panicle neck length (PNL), for hybrid rice seed production, it is possible to avoid the procedure of cutting flag leaves and make the supplementary pollination feasible by machine. In this study, a japonica restorer C-bao as the receptor parent and a primitive japonica accession Ludao as the donor parent were used to construct a chromosome segment substitution line (CSSL) population. The CSSL population was used to detect quantitative trait loci (QTLs) for the four outcrossing traits using a likelihood ratio test based on the stepwise regression (RSTEP-LRT) method. The CSSL population constructed consisted of 163 lines covering 90.7% of the donor genome. Among the seven QTLs detected in the CSSL population, four QTLs were detected in both years. qFLL-4 explained 6.70% of the two-year-averaged phenotypic variance, and the alleles from Ludao decreased FLL 5.1 cm. qFLA-1.1 and qFLA-1.2 explained 7.85% and 21.29% of the 2-year-averaged phenotypic variance respectively, and the alleles from Ludao increased FLA 17.38° and 31.50°. qPNL-8 explained 8.87% of the 2-year-averaged phenotypic variance, and the alleles from Ludao increased PNL 4.44 cm. These favorable alleles identified could be used to improve the outcrossing traits of parents for hybrid rice seed production in rice.

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Relationship between Yield and Yield Contributing Traits in Sorghum [Sorghum bicolor (L) Moench]

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2021/v33i2430779 ◽

2021 ◽

pp. 283-288

Author(s):

P. Vinoth ◽

B. Selvi ◽

N. Senthil ◽

K. Iyanar ◽

S. Jeyarani ◽

...

Keyword(s):

Grain Yield ◽

Direct Effect ◽

Seed Weight ◽

Flag Leaf ◽

Positive Association ◽

Leaf Length ◽

Panicle Length ◽

Area Index ◽

Flag Leaf Length ◽

Panicle Weight

Knowledge about the association between grain yield and yield contributing traits is important for sorghum development programs. Thus, the aim of this study was to determine correlations and path-coefficients between grain yield per plant and yield contributing traits. The experiment was conducted during Kharif 2019 in the Department of millets, TNAU, Coimbatore, India by using nine parents and twenty hybrids to study the genotypic correlations on the basis of seventeen traits. Analysis of variance evinced significant variation for all the traits under study. In correlation studies, the grain yield was positively associated with plant height (0.603), leaf length (0.613), leaf area index (0.501), flag leaf length (0.529), panicle length (0.608), panicle weight (0.930) and hundred seed weight (0.643). In path analysis, the traits leaf length, flag leaf length, panicle length, panicle weight and hundred seed weight exposed highly direct and indirect effects. Selection for a trait is effective when both the correlation and direct effect are higher and positive as this indicates its true association. Hence this investigation revealed flag leaf length, panicle length, panicle weight and hundred seed weight exhibited positive association and direct effect on grain yield, which indicates that the selection towards these characters will improve the yield.

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Genetic divergence studies on upland rice grown in Nagaland, India

Indian Journal of Agricultural Research ◽

10.18805/ijare.v50i6.6673 ◽

2016 ◽

Vol 50 (6) ◽

Author(s):

Jogendra Singh ◽

Toshimenla M. Toshimenla ◽

Sapu Changkija

Keyword(s):

Seed Yield ◽

Genetic Divergence ◽

Seed Weight ◽

Upland Rice ◽

Panicle Length ◽

Genotype 1 ◽

Cluster Distance ◽

Minimum Number ◽

100 Seed Weight ◽

Panicle Weight

Genetic divergence was studied in a set of seventy four genotypes of upland rice by using Mahalanobis D2 statistics for yield and its contributing characters. All the characters under study showed highly significant differences among genotypes. The genotypes under study were grouped into 15 clusters. The distribution pattern indicated that maximum number of genotypes (35) were found in cluster I, followed by cluster II with 12 genotypes, whereas, minimum number of genotype (1) had cluster XV. The inter-cluster distance was greater than intra-cluster distance indicating wide genetic divergence among genotypes. The highest intra-cluster distance was revealed in cluster XIV followed by cluster XIII and cluster XI. The maximum inter-cluster distance was observed between Cluster XIV and XV, followed by Cluster V and XV. The highest cluster mean was observed for yield/plant in cluster VII; however, contributing characters viz., panicle length, panicle weight, filled grains and 100 seed weight were found in cluster XIV. Seed yield/plant was found major contributing character towards the total genetic divergence which may be utilized in selecting genetically diverse parents, especially for exploitation of heterosis.

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Identification of variability for agronomically important traits in rice mutant families

Bragantia ◽

10.1590/1678-4499.283 ◽

2016 ◽

Vol 75 (1) ◽

pp. 41-50 ◽

Cited By ~ 6

Author(s):

Viviane Kopp da Luz ◽

Solange Ferreira da Silveira Silveira ◽

Gabriela Magalhães da Fonseca ◽

Eder Licieri Groli ◽

Ricardo Garcia Figueiredo ◽

...

Keyword(s):

Plant Height ◽

Agronomic Traits ◽

Oryza Sativa L ◽

Flag Leaf ◽

Grain Weight ◽

Superior Performance ◽

Yield Potential ◽

Panicle Length ◽

Rice Mutant ◽

Panicle Weight

ABSTRACT The increase of yield potential in new rice (Oryza sativa L.) varieties has been a major challenge for genetic improvement. The generation of mutants, followed by their characterization, constitutes a great possibility to isolate and select genes and genotypes that present agronomic traits of interest. This study aimed to evaluate the effect of chemical mutagen ethyl methane sulphonate (EMS) on agronomic traits in 340 M3 families of rice derived from BRS Querência cultivar. Seeds from each family and the original genotype BRS Querência were sown in the experimental field, and the characters main panicle length, main panicle weight, main panicle grain weight, flag leaf width and plant height were evaluated. Data were subjected to analysis of variance (p ≤ 0.05), and a comparison of means was carried out by Dunnett's test at 5% significance. The results show that there is genetic variability among the mutant families, suggesting that the mutagen EMS at 1.5% is effective for generating mutants for all assessed traits. Among the characters, plant height was the most affected by the mutagen, which provided an increase in the character. For the main panicle length character, seven families showed means above the control; for main panicle weight and grain weight, four and six mutant families were observed, respectively, with a superior performance in comparison to the control.

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Assessment of Appropriate Doses of GA3 and Row Ratio for Better Seed Yield of a Promising Hybrid Rice Variety

Bangladesh Rice Journal ◽

10.3329/brj.v19i1.25221 ◽

2015 ◽

Vol 19 (1) ◽

pp. 57-61

Author(s):

MJ Hasan ◽

MH Rahman ◽

A Akter ◽

MU Kulsum ◽

A Islam

Keyword(s):

Field Experiment ◽

Seed Production ◽

Seed Yield ◽

Hybrid Rice ◽

Rice Variety ◽

Dry Season ◽

Hybrid Seed ◽

Hybrid Seed Production ◽

Research Institute

A field experiment was carried out at the Bangladesh Rice Research Institute (BRRI) farm, Gazipur during dry season 2013-14 to find out the appropriate GA3 dose and row ratio for hybrid seed production. GA3 doses were applied @ 0, 80, 160, 240 and 320 g ha-1 with different row ratio. Results revealed that GA3 application influenced the panicle exsertion rate only. The calculated optimum GA3 dose was 302.4 g ha-1 with the highest PER (84.62%). Seed yield and OCR were influenced by row ratio. The highest OCR was observed with 2:12 row ratio while the highest seed yield was found in 2:14 row ratio.Bangladesh Rice j. 2015, 19(1): 57-61

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QTL Mapping of Novel Genomic Regions for Yield Related Traits in Doubled Haploid (DH) Population Derived from the Popular Rice Hybrid KRH-2

10.21203/rs.3.rs-62169/v1 ◽

2020 ◽

Author(s):

Swapnil Ravindra Kulkarni ◽

Balachandran Sena Munuswamy ◽

Ulaganathan K ◽

Divya Balakrishnan ◽

Hari Prasad A.S. ◽

...

Keyword(s):

Grain Yield ◽

Doubled Haploid ◽

Flag Leaf ◽

Major Effect ◽

Leaf Length ◽

Minor Effect ◽

Panicle Length ◽

Flag Leaf Width ◽

Flag Leaf Length ◽

Panicle Weight

Abstract Background: Rice, being the principal food crop and major nutritional source for more than half of the global population, is also an important source of livelihood in many South and South-East Asian countries. Amidst diminishing natural resources and many biotic-abiotic stresses, increasing the yield of rice varieties remains a challenging task. Identification of novel and yield augmenting alleles from stable rice hybrids is crucial to facilitate their marker-assisted transfer into various genetic backgrounds. Results: Quantitative trait loci (QTL) mapping using a population of 125 doubled haploid (DH) lines developed from the cross IR58025A/KMR3R and 126 polymorphic SSR; EST-derived SSR markers led to the identification of 12 each of major-minor effect QTLs for yield related traits. Major effect QTLs were detected for traits namely days to fifty percent flowering, test (1,000) grain weight, plant height, panicle weight, panicle length, flag leaf width, flag leaf length, biomass and total grain yield/plant explaining the phenotypic variability in the range of 29.95%-56.75%. QTL hotspots were detected on chromosome 3 for the traits, panicle length and total grain yield/plant and on chromosome 6 for the traits, panicle length, flag leaf length and total grain yield/plant. Though many of these QTLs were noted to co-localize with the QTL regions reported in earlier studies, five novel and major effect QTLs for panicle length, biomass, flag leaf width, panicle weight, plant height and three novel minor effect QTLs for panicle weight and fertile grains per panicle, were identified in this study. Conclusions: Through this study, both major-minor effect novel QTLs for crucial yield related traits, viz., fertile grains per panicle, panicle length, panicle weight were identified. Further, the QTL hotspots identified on two different chromosomes for flag leaf length, panicle length and total grain yield/plant shall not only help in understanding the underlying genetic mechanisms of yield regulation but also would provide an insight into the genetic synchrony among the various yield related traits in contributing for yield heterosis. The identified QTL hotspots after their validation can be deployed in breeding programs targeted towards improvement of yield heterosis.

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Effects of Gibberellic Acid Application after Anthesis on Seed Vigor of Indica Hybrid Rice (Oryza sativa L.)

Agronomy ◽

10.3390/agronomy9120861 ◽

2019 ◽

Vol 9 (12) ◽

pp. 861

Author(s):

Xiaomin Wang ◽

Huabin Zheng ◽

Qiyuan Tang ◽

Wenwei Mo ◽

Junjie Ma

Keyword(s):

Gibberellic Acid ◽

Seed Production ◽

Seed Yield ◽

Field Experiments ◽

Hybrid Rice ◽

Seed Vigor ◽

Rice Seed ◽

Germination Test ◽

Vigor Index ◽

Indica Hybrid Rice

Gibberellic acid (GA3) application after anthesis is an important practice in hybrid rice seed production, and it plays diverse roles in seed quality and seed yield. The main objective of this study was to determine (1) the effects of GA3 application after anthesis on seed vigor and (2) the optimal GA3 dosage applied to Indica hybrid rice seed production. Field experiments of different GA3 dosages (15 g hm−2 and 30 g hm−2, respectively) after anthesis were conducted in 2016 and 2017, and seed vigor parameters, stigma vigor index, and seed yield were determined. We found that significant differences in seed vigor parameters by a standard germination test and a cool germination test were observed among different GA3 dosages after anthesis. Compared with the water spraying treatment, the germination percentage (GP) increased by 2.5–6.3%, and the vigor index (VI) increased by 8.9–19.8% from GA3 application after anthesis, respectively. Moreover, the stigma vigor index of the female parent was enhanced with an increasing GA3 dosage, and there were significant increases (7.5–16.0%) between the water spraying treatment and GA3 spraying treatments. There were positive significant relationships between the VI and stigma vigor index. Additionally, the seed yield of the GA3 application with 30 g hm−2 was 3.9% higher on average than that of the water spraying treatment. Therefore, our study suggests that seed vigor can be increased by GA3 application after anthesis, and GA3 application should be applied at a rate of 30 g hm−2 to improve seed vigor and maintain seed yield in Indica hybrid rice seed production.

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Hybrid rice development in Indonesia: constraints and opportunities

E3S Web of Conferences ◽

10.1051/e3sconf/202130601047 ◽

2021 ◽

Vol 306 ◽

pp. 01047

Author(s):

Satoto ◽

Yuni Widyastuti

Keyword(s):

Seed Production ◽

Seed Yield ◽

Hybrid Rice ◽

Hybrid Seed ◽

Rice Seed ◽

Hybrid Seed Production ◽

Rice Varieties ◽

Private Companies ◽

Climatic Fluctuations ◽

Seed Grower

This paper reviews the constraints and opportunities of hybrid rice development in Indonesia. Indonesia has released more than a hundred hybrid rice varieties; Indonesian Center for Rice Research (ICRR) developed 21 varieties. Extensive trials were conducted on the various aspects of seed production by government sectors and private companies. Significant progress has been made in hybrid rice seed production, with seed yield increasing from 1 t/ha to 3 t/ha. Various problems should be considered to develop a good seed production system. The constraints are the low outcrossing rate, shortage of suitable land, high cost and labor, lack of trained personnel, climatic fluctuations in rainfall and temperature, and limited hybrid rice seed grower. Private sectors investment in hybrid rice has been increased. Positive support from government and private companies will boost hybrid rice’s adoption rapidity. Collaboration of hybrid rice dissemination across institutions was a meaningful way to encourage hybrid rice adoption. Optimizing seed production technologies could significantly increase the present level of hybrid seed yield. The opportunities are an increase of rice demand, various materials genetic, distribution of rice ecosystem, and public-private sector partnership that developed on hybrid seed production to accelerate the adoption of hybrid rice. It supports not only the research and development but also the dissemination and adoption.

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Study on floral traits and seed setting in parental lines of hybrid rice during early ahu and kharif seasons

Indian Journal of Genetics and Plant Breeding (The) ◽

10.31742/ijgpb.78.3.2 ◽

2018 ◽

Vol 78 (3) ◽

Author(s):

Aradhana Phukan ◽

P. K. Barua ◽

D. Sarma ◽

S. D. Deka

Keyword(s):

Seed Set ◽

Flag Leaf ◽

Pollen Dispersal ◽

Pollen Sterility ◽

Leaf Length ◽

Floral Traits ◽

Opening Angle ◽

Leaf Angle ◽

Seed Setting ◽

Parental Lines

Two CMS lines, IR 58025A and IR 68888A along with their maintainers and two fertility restorers, LuitR and IR 36R, were evaluated for flower and plant characters during early ahu (February-June) and kharif (July-November) seasons. IR 58025A showed longer stigmata and styles, and higher spikelet Length/Breadth (L/B) ratio while IR 68888A showed broader stigmata and wider glume opening angle in both the seasons. IR 68888A also exhibited higher pollen sterility during early ahu. IR 36R was characterized with broad anthers. LuitR showed longer and broader anthers with more pollen than others. Plant height, flag leaf length, flag leaf width and area were higher in IR 36R. Panicle exsertion was complete in pollen parents whereas it was 78-80% in CMS lines. The widest flag leaf angle was found in IR 58025B during early Ahu and in IR 36R during kharif. Kharif season was more favourable for growth of the plants with higher seed set percentage while floral traits of the CMS lines were better expressed in early Ahu. Manipulation of the seeding sequence of the parental lines in early Ahu is warranted for better seed set provided the seed crop escapes heavy premonsoon showers during reproductive stage. IR 68888A/LuitR was a good combination for pollen dispersal and seed setting.

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