scholarly journals QTL Mapping of a Novel Genomic Region Associated with High Out-Crossing Rate Derived from Oryza longistaminata and Development of New CMS Lines in Rice, O. sativa L.

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
G. D. Prahalada ◽  
Balram Marathi ◽  
Ricky Vinarao ◽  
Sung-Ryul Kim ◽  
Reynaldo Diocton ◽  
...  
Keyword(s):  
Seed Production ◽  
Pollen Grains ◽  
Interval Mapping ◽  
Major Effect ◽  
Genomic Region ◽  
Floral Traits ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Oryza Longistaminata ◽  
Male Donor

AbstractHigh seed cost due to poor seed yield severely limits the adoption of hybrid rice by farmers. Increasing the out-crossing rate is one of the key strategies to increase hybrid seed production. Out-crossing rate is highly influenced by the size of female floral traits, which capture pollen grains from male donor plants. In the current study, we identified 14 QTLs derived from the perennial wild rice Oryza longistaminata by composite interval mapping for five key floral traits: stigma length (five), style length (three), stigma breadth (two), stigma area (one), and pistil length (three). QTL analysis and correlation studies revealed that these stigma traits were positively correlated and pleiotropic to the stigma length trait. We selected the major-effect QTL qSTGL8.0 conferring long stigma phenotype for further fine mapping and marker-assisted selection. The qSTGL8.0 (~ 3.9 Mb) was fine mapped using newly developed internal markers and was narrowed down to ~ 2.9 Mb size (RM7356–RM256 markers). Further, the flanking markers were validated in a segregating population and in progenies from different genetic backgrounds. The markers PA08-03 and PA08-18 showed the highest co-segregation with the stigma traits. The qSTGL8.0 was introgressed into two cytoplasmic male sterile (CMS) lines, IR58025A and IR68897A, by foreground, background, and trait selection approaches. The qSTGL8.0 introgression lines in CMS backgrounds showed a significantly higher seed setting rate (2.5–3.0-fold) than the original CMS lines in test crosses with their corresponding maintainer lines. The newly identified QTLs especially qSTGL8.0, will be quite useful for increasing out-crossing rate and this will contribute to increase seed production and decrease seed cost.

scholarly journals QTL Fine Mapping of a Novel Genomic Region Associated With High Out-crossing Rate Derived From Oryza Longistaminata and Development of New CMS Lines in Rice, O. Sativa L.

2021 ◽  
Author(s):  
G.D. Prahalada ◽  
Balaram Marathi ◽  
Ricky Vinarao ◽  
Sung-Ryul Kim ◽  
Reynaldo Diocton ◽  
...  
Keyword(s):  
Seed Production ◽  
Fine Mapping ◽  
Pollen Grains ◽  
Interval Mapping ◽  
Major Effect ◽  
Genomic Region ◽  
Floral Traits ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Oryza Longistaminata

Abstract Background: High seed cost due to poor seed yield severely limits the adoption of hybrid rice by farmers. Increasing the out-crossing rate is one of the key strategies to increase hybrid seed production. Out-crossing rate is highly influenced by the size of female floral traits, which capture pollen grains from male donor plants. Results: In the current study, we identified 14 QTLs derived from the perennial wild rice Oryza longistaminata by composite interval mapping for five key floral traits: stigma length (five), style length (three), stigma breadth (two), stigma area (one), and pistil length (three). QTL analysis and correlation studies revealed that these stigma traits were positively correlated and pleiotropic to the stigma length trait. We selected the major-effect QTL qSTGL8.0 conferring long stigma phenotype for further fine mapping and marker-assisted selection (MAS). The qSTGL8.0 (~3.9 Mb) was fine mapped using newly developed internal markers and was narrowed down to ~2.9 Mb size (RM7356‒RM256 markers). Further, the flanking markers were validated in a segregating population and in progenies from different genetic backgrounds. The markers PA08-03 and PA08-18 showed the highest co-segregation with the stigma traits. The qSTGL8.0 was introgressed into two cytoplasmic male sterile (CMS) lines, IR58025A and IR68897A, by foreground, background, and trait selection approaches. Conclusion: The qSTGL8.0 introgression lines in CMS backgrounds showed a significantly higher seed setting rate (2.5‒3.0-fold) than the original CMS lines in testcrosses with their corresponding maintainer lines. The newly identified QTLs especially qSTGL8.0, will be quite useful for increasing out-crossing rate and this will contribute to increase seed production and decrease seed cost.

scholarly journals Male Sterility and its Commercial Exploitation in Hybrid Seed Production of Vegetable Crops: A Review

2019 ◽  
Vol 40 (04) ◽  
Author(s):  
Pramod Sharma ◽  
Sunil A Nair ◽  
Payal Sharma
Keyword(s):  
Male Sterility ◽  
Seed Production ◽  
Large Scale ◽  
Pollen Grains ◽  
Hybrid Seed ◽  
Scale Production ◽  
Hybrid Seed Production ◽  
Vegetable Crops ◽  
Male Sterile ◽  
Large Scale Production

Male sterility is described as absence of functional pollen grains in hermaphrodite flowers facilitating large scale production of hybrid seeds in vegetable crops. It eases hybrid seed production at commercial level in crops like tomato, chilli, capsicum, carrot, onion, cabbage, cauliflower and cucurbits. Male sterility would reduce the cost of hybrid seed production by limiting the labour making it efficient and economical. Incorporation of biotechnological tools in conventional plant breeding techniques would aid the breeders in limiting the drawbacks surrounding exploitation of male sterility for development of new hybrids. The present review is an attempt to summarize and to know the commercial utilization of male sterile line in hybrid seed production of vegetables.

scholarly journals Potential Association of Reactive Oxygen Species With Male Sterility in Peach

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaming Cai ◽  
Zhishen Ma ◽  
Collins Otieno Ogutu ◽  
Lei Zhao ◽  
Liao Liao ◽  
...  
Keyword(s):  
Male Sterility ◽  
Pollen Grains ◽  
Hybrid Vigor ◽  
Abnormal Development ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Potential Association ◽  
Genetic Mechanisms ◽  
Ros Burst ◽  
Underlying Mechanisms

Male sterility is an important agronomic trait for hybrid vigor utilization and hybrid seed production, but its underlying mechanisms remain to be uncovered. Here, we investigated the mechanisms of male sterility in peach using a combined cytology, physiology, and molecular approach. Cytological features of male sterility include deformed microspores and tapetum cells along with absence of pollen grains. Microspores had smaller nucleus at the mononuclear stage and were compressed into belts and subsequently disappeared in the anther cavity, whereas tapetum cells were swollen and vacuolated, with a delayed degradation to flowering time. Male sterile anthers had an ROS burst and lower levels of major antioxidants, which may cause abnormal development of microspores and tapetum, leading to male sterility in peach. In addition, the male sterility appears to be cytoplasmic in peach, which could be due to sequence variation in the mitochondrial genome. Our results are helpful for further investigation of the genetic mechanisms underlying male sterility in peach.

scholarly journals CHARACTERIZATION OF A MALE-STERILE SYSTEM WITH A CLOSELY LINKED SEEDLING MARKER TO FACILITATE F1 HYBRID TOMATO SEED PRODUCTION

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1168e-1168 ◽  
Author(s):  
Edward C. Tigchelaar
Keyword(s):  
Male Sterility ◽  
Seed Production ◽  
Marker Gene ◽  
Hybrid Seed ◽  
Hybrid Seed Production ◽  
Chromosome 2 ◽  
Male Sterile ◽  
Tomato Seed ◽  
F1 Hybrid

The coupling phase linkages have been synthesized between the gene aw (without anthocyanin) and the male sterile gene ms15 (and its alleles ms26, ms47, and an Israeli source of male sterility). Less than 2 map units separate aw and ms15 on chromosome 2, providing a convenient seedling marker gene to rapidly identify male sterility for both inbred development and hybrid seed production. The seedling marker also provides a convenient marker to rapidly assess hybrid seed purity. Unique features of each of the alleles involved in male sterility and their use in inbred and hybrid development will be described.

scholarly journals First Report of Sorghum Ergot Caused by Claviceps africana in the United States

Plant Disease ◽  
1998 ◽  
Vol 82 (5) ◽  
pp. 592-592 ◽  
Author(s):  
T. Isakeit ◽  
G. N. Odvody ◽  
R. A. Shelby
Keyword(s):  
Seed Production ◽  
The United States ◽  
Grain Sorghum ◽  
Hybrid Seed ◽  
High Plains ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Production Region ◽  
Corpus Christi ◽  
Chromatography Analysis

In March 1997, ergot was found on sorghum (Sorghum bicolor (L.) Moench) regrowth in several abandoned commercial grain sorghum fields in Cameron and Hidalgo counties in the Lower Rio Grande Valley (LRGV) of Texas. White sphacelia in florets produced honeydew containing macrospores (hyaline, oblong to oval, 10 to 25 μm × 5 to 7 μm) and microspores (hyaline, spherical, 3 μm in diameter). Macrospores germinated iteratively to form secondary conidia when placed on water agar and in situ following rain. Secondary conidia were hyaline, pyriform, with a protruding hilum, and measured 10 to 17 μm × 5 to 7 μm. High-pressure liquid chromatography analysis detected the alkaloid di-hydroergosine in sphacelia, which is unique to C. africana (1). The pathogen was also confirmed on adjacent johnsongrass (S. halepense). The spread of ergot across Texas was associated with the progressive maturation of the commercial sorghum crop as follows: LRGV (mid-May), Coastal Bend near Corpus Christi (June), Winter Garden area southwest of San Antonio (July), and the seed production region of the Texas Panhandle (mid-August). Ergot incidence ranged from a trace to 10% of the heads in (self-fertile) grain sorghum fields of the LRGV. Most heads had only a few infected florets, but a few heads had 35 to 50% of the florets infected. Only trace amounts were found in grain sorghum fields in other areas of the state. Incidence and severity of ergot were greatest in fields of male-sterile sorghums grown for forage. Ergot was generally low in primary heads of male-sterile sorghums in hybrid seed production fields but, in the absence of pollen, axillary tillers sometimes developed high levels of ergot. The major impact of sorghum ergot is expected to be in hybrid seed production fields in the High Plains of Texas. Reference: (1) D. E. Frederickson et al. Mycol. Res. 95:1101, 1991.

SELECTION FOR CROSS-POLLINATION IN BARLEY USING SEGREGATING BULK POPULATIONS

1981 ◽  
Vol 61 (1) ◽  
pp. 17-24 ◽  
Author(s):  
K. W. CAMPBELL ◽  
K. J. KASHA
Keyword(s):  
Seed Production ◽  
Selection Pressure ◽  
Seed Set ◽  
Hybrid Seed Production ◽  
Average Difference ◽  
Male Sterile ◽  
Cross Pollination ◽  
Regular Cycle ◽  
Growth Room ◽  
Selection For

Six bulk populations, each containing a recessive male sterile gene, were used to determine the level of cross-pollination of barley in Ontario for hybrid seed production. Selection pressure for characters that favor cross-pollination was applied by harvesting only male sterile plants to provide seed for the next generation. Seed set on male sterile plants fluctuated greatly from year to year (10.5–51.0%) with no constant trend upward or downward over a 6-yr period from 1968 to 1973. There were no differences in seed set bulk populations grown from remnant seed from previous cycles and from the regular cycle material in 1971 when seed set was low in all populations. However, the same procedure in 1972 provided an average difference of 22.5% in seed set in favor of the advanced selected populations. Cross-pollination was not improved by one cycle of selection under growth room conditions for characters associated with cross-pollination. The influence of a self-pollinated winter increase upon improvement in the level of cross-pollination is discussed. Results indicated that cross-pollination is not sufficient or reliable enough to produce hybrid barley seed in the area tested.

Alfalfa leafcutting bee (Hymenoptera: Megachilidae) pollination of oilseed rape (Brassica napus L.) under isolation tents for hybrid seed production

2001 ◽  
Vol 81 (1) ◽  
pp. 199-204 ◽  
Author(s):  
J. J. Soroka ◽  
D. W. Goerzen ◽  
K. C. Falk ◽  
K. E. Bett
Keyword(s):  
Brassica Napus ◽  
Seed Production ◽  
Oilseed Rape ◽  
Hybrid Seed ◽  
Hybrid Seed Production ◽  
Stocking Rate ◽  
Megachile Rotundata ◽  
Male Sterile ◽  
Brassica Napus L ◽  
Stocking Rates

In this 3-yr field study, the activities of alfalfa leafcutting bees (Megachile rotundata Fabricius) (LCB) at varying stocking levels were monitored in shade cloth isolation tents containing male-sterile and male-fertile rows of oilseed rape Brassica napus L. to determine optimum conditions for hybrid seed production. Bumble bees, Bombus impatiens Cresson, were similarly tested in 1 yr; their pollination activities were minimal, and weight of seed produced on female lines in tents containing bumble bees was similar to that in tents without pollinators. Leafcutting bee activity, as measured by the number of female bees at the entrance to tunnels in the hive, at first increased, then decreased with increasing stocking rate. Duration of time spent visiting flowers did not vary with stocking rate, but was longer on male-fertile than on male-sterile flowers. Production of hybrid seed within tents varied with leafcutting bee stocking rate, with the highest seed yield achieved at stocking rates equivalent to three charges at weekly intervals of 400 000 leafcutting bees per hectare. At optimum LCB stocking rates, the method described provided sufficient seed quantity for small-plot multi-location field evaluation of oilseed rape hybrids. Key words: Megachile rotundata, alfalfa leafcutting bee, Bombus impatiens, Brassica napus, oilseed rape, hybrid seed production, isolation tents

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