Hand-Tripped Flowers Promote Seed Production in Arachis lignosa, a Wild Peanut1

1990 ◽  
Vol 17 (1) ◽  
pp. 22-24 ◽  
Author(s):  
Donald J. Banks

Abstract In trials conducted in the greenhouse, growth chamber, and outdoors, no pegs or pods were produced when A. lignosa (Chod. et Hassl.) Krap. et Greg. nom. nud. plants were allowed to pollinate naturally. However, hand tripping flowers, especially in the greenhouse, resulted in significant increases in pod production. The results suggest that the high degree of reproductive sterility usually noted for A. lignosa in culture is due to pollination failure rather than to physiological self incompatibility. The somewhat truncated shape of the stigma and its elevated position relative to the anthers probably restricts natural self-pollination without the aid of pollinating vectors such as bees.

1997 ◽  
Vol 77 (1) ◽  
pp. 69-73 ◽  
Author(s):  
T. A. Campbell ◽  
Y. He

Self-incompatibility (seeds/pod and seeds/floret tripped) was evaluated in the growth chamber (27°C) using a 6 × 6 factorial arrangement. Parents represented a broad range of self-compatibility and were selected on the basis of stability of autogamous seed production in the greenhouse and growth chamber. Additive genetic variation appeared to be most important, indicating that a mass selection scheme such as recurrent phenotypic selection would be effective in increasing levels of self-incompatibility in at least some alfalfa populations. Narrow-sense heritability estimates for seeds/pod and seeds/floret tripped were 0.23 (SE = 0.09) and 0.28 (SE = 0.06), respectively. There is a direct relationship between autogamous seed production and pollen production, however, results of this experiment indicate that there may be considerable variation in pollen production, germination and vigor among self-incompatible clones. Increased seed set resulting from self-incompatible × self-incompatible crosses could be a function of greater gamete selection in the self-incompatible parents (due to deleterious genes), improved pollen germination, and hybrid vigor in pollen tube growth. Key words: Medicago sativa L., autogamy, allogamy, hybrid


Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 432
Author(s):  
Yaling Chen ◽  
Benchang Hu ◽  
Fantao Zhang ◽  
Xiangdong Luo ◽  
Jiankun Xie

Dendrobium officinale is a rare and traditional medicinal plant with high pharmacological and nutritional value. The self-incompatibility mechanism of D. officinale reproductive isolation was formed in the long-term evolution process, but intraspecific hybridization of different germplasm resources leads to a large gap in the yield, quality, and medicinal value of D. officinale. To investigate the biological mechanism of self-incompatibility in D. officinale, cytological observation and the transcriptome analysis was carried out on the samples of self-pollination and cross-pollination in D. officinale. Results for self-pollination showed that the pollen tubes could grow in the style at 2 h, but most of pollen tubes stopped growing at 4 h, while a large number of cross-pollinated pollen tubes grew along the placental space to the base of ovary, indicating that the self-incompatibility of D. officinale may be gametophyte self-incompatibility. A total of 63.41 G basesum of D. officinale style samples from non-pollinated, self-pollination, and cross-pollination by RNA-seq were obtained, and a total of 1944, 1758, and 475 differentially expressed genes (DEGs) in the comparison of CK (non-pollinated) vs. HF (cross-pollination sample), CK vs. SF (self-pollination sample) and SF vs. HF were identified, respectively. Forty-one candidate genes related to self-incompatibility were found by function annotation of DEGs, including 6 Ca2+ signal genes, 4 armed repeat containing (ARC) related genes, 11 S-locus receptor kinase (SRK) related genes, 2 Exo70 family genes, 9 ubiquitin related genes, 1 fatty acid related gene, 6 amino acid-related genes, 1 pollen-specific leucine-rich repeat extensin-like protein (LRX) related gene and 1 lectin receptor-like kinases (RLKs) related gene, showed that self-incompatibility mechanism of D. officinale involves the interaction of multiple genes and pathways. The results can provide a basis for the study of the self-incompatibility mechanism of D. officinale, and provide ideas for the preservation and utilization of high-quality resources of D. officinale.


1976 ◽  
Vol 54 (22) ◽  
pp. 2530-2535 ◽  
Author(s):  
Fred R. Ganders

Stigmatic pollen loads were analyzed from naturally pollinated pin and thrum form flowers of Amsinckia douglasiana and A. vernicosa var. furcata. Pin stigmas captured more total pollen than thrum stigmas. Pins experienced either net self-pollination or random pollination. Thrum stigmas experienced significant disassortative pollination. Comparing pollen loads from intact and emasculated thrum flowers of A. douglasiana indicated that self-pollination and geitonogamy were relatively unimportant in the pollination of the thrum form. The level of disassortative pollination of A. vernicosa var. furcata does not appear to be high enough to account for the level of disassortative mating observed by progeny testing, suggesting that this species may possess an incomplete stylar self-incompatibility system such as has been reported in A. grandiflora.


Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1587-1597 ◽  
Author(s):  
Katsunori Hatakeyama ◽  
Takeshi Takasaki ◽  
Masao Watanabe ◽  
Kokichi Hinata

Abstract In Brassica species that exhibit self-incompatibility, two genes, SLG and SRK, at the S locus are involved in the recognition reaction with self and non-self pollen. From a pollen-recessive S29 haplotype of Brassica rapa, both cDNA and genomic DNA clones for these two genes were isolated and characterized. The nucleotide sequence for the S domain of SRK29 showed a high degree of similarity with that of SLG29, and they belong to Class II type. RNA gel blot analysis showed that the transcript of SLG29 consisted of the first and second exons, and no other transcript containing any part of the intron sequence was detected. Because no transmembrane domain was encoded by the second exon of SLG29, SLG29 was designated a secreted type glycoprotein. SLGs of two other pollen-recessive haplotypes, S40 and S44, of B. rapa also had a similar structure to that of SLG29. Previously, SLG2 from a pollen-recessive haplotype, S2, of Brassica oleracea was found to produce two different transcripts, one for the secreted type glycoprotein and the other for a putative membrane-anchored form of SLG. Therefore, the nature of these SLGs from pollen-recessive haplotypes of B. rapa is different from that of SLG2 of B. oleracea.


1980 ◽  
Vol 58 (6) ◽  
pp. 712-716 ◽  
Author(s):  
Shirley Dobrofsky ◽  
W. F. Grant

Self-incompatibility, a prefertilization event, and self-sterility, a postfertilization event, have both been suggested as causes for differences in seed set between cross- and self-pollinated florets in Lotus corniculatus L. Ovary protein subunits of selfed, crossed, and unpollinated florets of L. corniculatus cv. Mirabel were studied using polyacrylamide gel electrophoresis. Banding patterns differed for all three conditions. Ovary protein differences were found prior to the time fertilization is known to occur, thereby providing evidence that self-incompatibility is at least partially responsible for the reduced seed set after self-pollination.


2016 ◽  
Vol 113 (49) ◽  
pp. 14145-14150 ◽  
Author(s):  
Zhenyi Chang ◽  
Zhufeng Chen ◽  
Na Wang ◽  
Gang Xie ◽  
Jiawei Lu ◽  
...  

The breeding and large-scale adoption of hybrid seeds is an important achievement in agriculture. Rice hybrid seed production uses cytoplasmic male sterile lines or photoperiod/thermo-sensitive genic male sterile lines (PTGMS) as female parent. Cytoplasmic male sterile lines are propagated via cross-pollination by corresponding maintainer lines, whereas PTGMS lines are propagated via self-pollination under environmental conditions restoring male fertility. Despite huge successes, both systems have their intrinsic drawbacks. Here, we constructed a rice male sterility system using a nuclear gene named Oryza sativa No Pollen 1 (OsNP1). OsNP1 encodes a putative glucose–methanol–choline oxidoreductase regulating tapetum degeneration and pollen exine formation; it is specifically expressed in the tapetum and miscrospores. The osnp1 mutant plant displays normal vegetative growth but complete male sterility insensitive to environmental conditions. OsNP1 was coupled with an α-amylase gene to devitalize transgenic pollen and the red fluorescence protein (DsRed) gene to mark transgenic seed and transformed into the osnp1 mutant. Self-pollination of the transgenic plant carrying a single hemizygous transgene produced nontransgenic male sterile and transgenic fertile seeds in 1:1 ratio that can be sorted out based on the red fluorescence coded by DsRed. Cross-pollination of the fertile transgenic plants to the nontransgenic male sterile plants propagated the male sterile seeds of high purity. The male sterile line was crossed with ∼1,200 individual rice germplasms available. Approximately 85% of the F1s outperformed their parents in per plant yield, and 10% out-yielded the best local cultivars, indicating that the technology is promising in hybrid rice breeding and production.


1986 ◽  
Vol 66 (1) ◽  
pp. 111-116
Author(s):  
R. P. KNOWLES

A yellow-seeded mutant of reed canarygrass resulting from close breeding was used to produce F1 hybrids with normal black-seeded strains. The vigor of the yellow-seeded parent was below that of standard cultivars but seed yield was significantly higher. Forage yields of hybrids from the free interpollination with black-seeded strains were equal to, but not above, those of recommended cultivars. A high degree of effective hybridization (80% or more) was obtained when sib lines, selfed lines, or synthetics of the yellow-seeded mutant were grown in alternate rows with black-seeded strains. Alternate three-row (3 m) groups of parents in the hybrid crossing block were convenient for machine harvesting of seed and resulted in good hybridization.Key words: Reed canarygrass, heterosis, incompatibility, seed production, pollination


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