scholarly journals Breeding of the Dormant Thermosensitive Genic Male-Sterile Lines of Early Rice to Overcome Pre-Harvest Sprouting of the Hybrid Seeds

Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 191 ◽  
Author(s):  
Xiaoyu Chen ◽  
Yun Tian ◽  
Xiangyang Lu
Keyword(s):  
High Temperature ◽  
Seed Dormancy ◽  
Wild Rice ◽  
Seed Quality ◽  
Hybrid Rice ◽  
Oryza Rufipogon ◽  
Rice Seed ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Early Rice

The pollen development of male-sterile lines should be conducted during the high temperature season to ensure the sterility of male-sterile line pollen and the safety of hybrid seed production in the breeding of thermosensitive genic male-sterile (TGMS) lines of early rice. However, the mature hybrid rice seeds are prone to pre-harvest sprouting (PHS) during hot, rainy days, which leads to the decrease of hybrid rice seed quality or a loss of utilization value. In this study, with an aim to bring a dormancy trait from the dormant genotype to the current low-dormant TGMS lines, a common wild rice “Chaling” (Oryza rufipogon), which has strong seed dormancy, a large black stigma, and a high exsertion rate, was hybridized with the early rice TGMS line “Zhu 1S,” which often exhibits PHS. After screening for early maturing and seed dormancy, the early rice “Yezao S” and “Yezhuzao S,” with the characteristic of seed dormancy, were selected. The critical temperature of high temperature sterility for these two male-sterile lines was below 23.5 °C. The stigma of “Yezao S” was black and its exsertion rate was 79.9%, while “Yezhuzao S” had a colorless stigma with an exsertion rate of 76.8%. The expression of the genes OsNCEDs in “Yezao S” and “Yezhuzao S” were significantly higher than that in “Zhu 1S” the 15th day after heading, and the abscisic acid (ABA) content was also higher than that of “Zhu 1S” the 20th day after heading. The results indicated that introducing the dormancy characteristics from wild rice “Chaling” into the early rice TGMS lines was an effective way to prevent PHS.

scholarly journals Production of Hybrid Rice seeds using environment sensitive genic male sterile (EGMS) and basmati rice lines in Kenya

2019 ◽  
Author(s):  
Njiruh Paul Nthakanio ◽  
Kariuki Simon Njau
Keyword(s):  
High Temperature ◽  
Hybrid Rice ◽  
Male Gamete ◽  
Growth Conditions ◽  
Basmati Rice ◽  
Rice Seed ◽  
Male Sterile ◽  
Male Gametes ◽  
Rice Seeds ◽  
The Impact

AbstractPhotoperiod-sensitive genic male sterile rice (PGMS) lines IR-73827-23-76-15-7 S, IR-75589-31-27-8-33S referred to as P1 and P2, and IR-77271-42-25-4-36S, thermo-sensitive genic male sterile (TGMS) line referred to as T were obtained from International Rice research Institute. These lines, collectively known as environment genic male sterile lines, were sown under greenhouse growth conditions where temperatures were more than 34°C with an objective of inducing complete male gamete sterility in them. Results indicated that high temperature growth conditions induces complete male gamete sterility in both the PGMS and TGMS lines. The impact of this is that, it will be possible to produce pure basmati hybrid rice seed in the tropical regions without contamination with pure breed lines. The male sterile PGMS/TGMS were pollinated with pollen from basmati370 and 217 grown under natural conditions and some hybrid seeds were obtained. This shows that high temperature emasculated the male gametes but not female ones. The conclusion is that it is possible to induce complete male gamete sterility in PGMS and TGMS under greenhouse in tropical growth conditions, and to produce hybrid rice seeds. This makes basmati hybrid rice seed production in Kenya a viable venture.

scholarly journals 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 ◽  
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.

scholarly journals Viability and Dormancy of Rice Seeds after Storage and Pre-Treatment with Dry Heat and Chemical Agents

2017 ◽  
Vol 9 (7) ◽  
pp. 175 ◽  
Author(s):  
Yvonne A. Mutinda ◽  
James W. Muthomi ◽  
John M. Kimani ◽  
George N. Cheminigw’wa ◽  
Florence M. Olubayo
Keyword(s):  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Seed Treatment ◽  
Room Temperature ◽  
Seed Quality ◽  
Packaging Material ◽  
Rice Seed ◽  
Dry Heat ◽  
Rice Seeds ◽  
Pre Treatment

Inappropriate seed packaging and seed dormancy affects seed quality and consequently leads to reduced crop stand, low seedling vigour and reduced yields. The objective of the study was to determine the effect of seed packaging material and seed treatment on viability and dormancy in rice seeds. Effect of packaging material was evaluated by storing freshly harvested seeds of Basmati 370 and BW 196 varieties in polythene, khaki, cheese cloth, polypropylene (Pp) sack and gunny bag sat room temperature and at 6 oC for six months. Effect of seed treatment on dormancy was determined by pre-treatment of seeds with nitric acid at 0.1 M, 0.2 M, 0.5 M, 1 M and 2 M, gibberellic acid (GA3) at 1000 ppm, 2000 ppm and 5000 ppm, and hydrogen peroxide at 0.5 M, 1 M, 2 M, 3 M, 5 M and dry heat at 50 oC for 48 hours. The seeds were subjected to germination test on moist paper and data on percentage germination, seedling length and seedling dry weight were taken. Packaging material had a significant (P ≤ 0.05) effect on germination and vigour. At room temperature, seed stored in polythene bag had the highest germination 88.2% and 57.8% for BW 196 and Basmati 370, respectively. Basmati 370 in khaki bag stored in the cold room had the highest germination 48.3%, while BW 196 stored in polythene had the highest (86.0%). Pre-treatment of seeds reduced dormancy, with variety BW 196 showing the highest germination of up to 67%, while variety Basmati 370 had the lowest germination of up to 40%. Gibberellic acid (GA3) at 5000 ppm was the most effective in breaking seed dormancy resulting in up to 95.7% germination. The results of the study indicated that packaging rice seed in polythene bags for periods not exceeding six months and pre-treatment with GA3 maintains high seed viability and breaks dormancy, respectively, thus ensuring rapid and uniform germination of vigorous seedlings. This would reduce the period farmers have to wait after harvest before they can plant newly harvested rice seeds.

scholarly journals Identification, Analysis, and Confirmation of Seed Storability-Related Loci in Dongxiang Wild Rice (Oryza rufipogon Griff.)

Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1831
Author(s):  
Minmin Zhao ◽  
Biaolin Hu ◽  
Yuanwei Fan ◽  
Gumu Ding ◽  
Wanling Yang ◽  
...  
Keyword(s):  
Wild Rice ◽  
Bulked Segregant Analysis ◽  
Oryza Rufipogon ◽  
Chromosome 9 ◽  
Rice Seed ◽  
Rice Varieties ◽  
Oryza Rufipogon Griff ◽  
Dongxiang Wild Rice ◽  
Candidate Loci ◽  
Seed Storability

Dongxiang wild rice (Oryza rufipogon Griff.) (DXWR) has strong seed storability and identifying its elite gene resources may facilitate genetic improvements in rice seed storability. In this study, we developed two backcross inbred lines (BILs) populations, with DXWR as a common donor parent and two rice varieties (F6 and R974) as recipient parents. Bulked segregant analysis via whole genome sequencing (BSA-seq) was used to identify seed storability-related loci in the DXWR and F6 population. Two main genomic regions containing 18,550,000–20,870,000 bp on chromosome 4 and 7,860,000–9,780,000 bp on chromosome 9 were identified as candidate loci of DXWR seed storability; these overlapped partially with seed storability-related quantitative trait loci (QTLs) discovered in previous studies, suggesting that these loci may provide important regions for isolating the responsible genes. In total, 448 annotated genes were predicted within the identified regions, of which 274 and 82 had nonsynonymous and frameshift mutations, respectively. We detected extensive metabolic activities and cellular processes during seed storability and confirmed the effects of the seed storability-related candidate loci using four BILs from DXWR and R974. These results may facilitate the cloning of DXWR seed storability-related genes, thereby elucidating rice seed storability and its improvement potential.

Effects of Different Dehydrating Agents on Seed Quality and Gene Expression in Hybrid Rice Seed Production

2017 ◽  
Vol 43 (9) ◽  
pp. 1308
Author(s):  
Hang-Qi SHEN ◽  
Wei-Min HU ◽  
Cheng LIN ◽  
Ya-Jing GUAN ◽  
Hong-You LIU ◽  
...  
Keyword(s):  
Gene Expression ◽  
Seed Production ◽  
Seed Quality ◽  
Hybrid Rice ◽  
Rice Seed

scholarly journals Molecular identification of the cytoplasmic male sterile source from Dongxiang wild rice (Oryza rufipogon Griff.)

2017 ◽  
Vol 16 (8) ◽  
pp. 1669-1675 ◽  
Author(s):  
Song YAN ◽  
Shan ZHU ◽  
Ling-hua MAO ◽  
Ren-liang HUANG ◽  
Hong-liang XIONG ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Wild Rice ◽  
Oryza Rufipogon ◽  
Male Sterile ◽  
Cytoplasmic Male Sterile ◽  
Oryza Rufipogon Griff ◽  
Dongxiang Wild Rice

Improvement of bacterial blight resistance of hybrid rice in China using the Xa23 gene derived from wild rice (Oryza rufipogon)

2011 ◽  
Vol 30 (6) ◽  
pp. 637-644 ◽  
Author(s):  
Yong-Li Zhou ◽  
Veronica N.E. Uzokwe ◽  
Cong-He Zhang ◽  
Li-Rui Cheng ◽  
Lei Wang ◽  
...  
Keyword(s):  
Wild Rice ◽  
Bacterial Blight ◽  
Hybrid Rice ◽  
Oryza Rufipogon ◽  
Blight Resistance ◽  
Bacterial Blight Resistance

scholarly journals Characteristics of Fertility Transition Response to the Cumulative Effective Low Temperature in a Two-Line Male Sterile Rice Cultivar

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Linxuan Wu ◽  
Huazhen Rong ◽  
Chun Chen ◽  
Xin Lin ◽  
Jiafeng Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Seed Production ◽  
Pollen Fertility ◽  
Hybrid Rice ◽  
Fertility Transition ◽  
Day Length ◽  
Sensitive Period ◽  
Rice Seed ◽  
Night Temperature ◽  
Male Sterile

Abstract Background Photo-thermo-sensitive genic male sterile (PTGMS) rice (Oryza sativa L.) is usually considered two-line male sterile rice because of its dual-purpose in two-line hybrid rice system: under short days and low temperatures, it is fertile and used for self-propagation, but under long days and high temperatures, it is sterile and used for hybrid seed production. Therefore, photoperiod and temperature conditions are extremely important for the fertility transition of two-line male sterile rice. In recent years, there have been frequent occurrences of abnormally low-temperature (ALT) resulting in failure of two-line hybrid rice seed production. The daily average temperature (DAT) during ALT events is sometimes higher than the critical sterility-inducing temperature (CSIT) of two-line male sterile rice, of which the night temperature is lower than the CSIT. DAT has been traditionally used as the single indicator of pollen fertility transition, but it is unknown why the fertility of two-line male sterile rice in seed production restored fertility under ALT conditions. Results For Hang93S (H93S), a newly released PTGMS line, we hypothesized fertility transition is determined mainly by the cumulative effective low temperature (ELT) and only a certain duration of low temperature is required every day during the fertility-sensitive period. This study simulated ALTs where the DAT was higher than the CSIT while some segments of night temperature were lower than the CSIT. The results showed H93S exhibited a fertility transition to varying degrees. Moreover, fertility was restored under simulated ALT conditions and pollen fertility increased with increasing cumulative ELT, indicating that the fertility transition was affected primarily by the cumulative ELT. Results also indicated that pollen fertility increased as the number of treatment days increased. Conclusions The fertility transition is caused mainly by the cumulative ELT. In two-line male sterile rice breeding, the effects of day length, ALT at night, and continuous response days should be considered together. The present study provides new insight into fertility transition so breeders can more effectively utilize the two-line male sterile rice, H93S, in breeding programs.

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