Self- and cross-incompatibility in Asparagus officinalis and Asparagus densiflorus cv. Sprengeri

1996 ◽  
Vol 74 (10) ◽  
pp. 1621-1625 ◽  
Author(s):  
O. N. Marcellán ◽  
E. L. Camadro

Garden asparagus, Asparagus officinalis L. (off), is dioecious and reproductively isolated from a related ornamental, monoecious Asparagus densifiorus (Kunth) Jessop cv. Sprengeri (spr). Since the latter is a potentially valuable source of germplasm, a study was initiated to identify hybridization barriers. Intra- and inter-specific crosses were made using 32 plants of two commercial cultivars of off and 17 plants of three introductions of spr. Part of the pollinated pistils were fixed and examined via fluorescence microscopy. In some combinations of genotypes, incompatibility reactions were detected: (i) off × off: in the stigmatic tissue, (ii) spr × spr: on the stigmatic surface and in the style, and (iii) spr × off: on the stigmatic surface, in the stigmatic tissue, and in the style. Although pollen tubes reached the ovules in most combinations of genotypes, seeds were only produced in intraspecific crosses. It is concluded that two types of internal barriers are acting: cross-incompatibility at the pollen–stigma and pollen–style levels, and stronger post-stylar barriers that had not been determined yet. Keywords: Asparagus densifiorus cv. Sprengeri, Asparagus officinalis, cross-incompatibility, reproductive isolation.


2013 ◽  
Vol 40 (No. 2) ◽  
pp. 65-71 ◽  
Author(s):  
D. Milatović ◽  
D. Nikolić ◽  
B. Krška

Self-(in)compatibility was tested in 40 new apricot cultivars from European breeding programmes. Pollen-tube growth in pistils from laboratory pollinations was analysed using the fluorescence microscopy. Cultivars were considered self-compatible if at least one pollen tube reached the ovary in the majority of pistils. Cultivars were considered self- incompatible if the growth of pollen tubes in the style stopped along with formation of characteristic swellings. Of the examined cultivars, 18 were self-compatible and 22 were self-incompatible. Fluorescence microscopy provides a relatively rapid and reliable method to determine self-incompatibility in apricot cultivars.      



1996 ◽  
Vol 76 (3) ◽  
pp. 493-497 ◽  
Author(s):  
T. C. Shinners ◽  
A. R. Olson

Monilinia vaccinii-corymbosi (Reade) Honey is an economically important pathogen of lowbush blueberry (Vaccinium angustifolium Aiton) which causes blighting of leaves and flowers and mummification of fruits. This study was conducted to determine if infection of lowbush blueberry gynoecia occurs through colonization of the stigma. Sections of gynoecia inoculated with conidia were examined by brightfield microscopy. Conidia germinated on the stigmatic surface 1–3 d following inoculation to form hyphae winch invaded the stylar canal and other tissue down to the ovules. The infection pathway observed was identical to that of pollen tubes following pollination. After invasion of the ovary fungal colonization continued until the entire fruit wall was colonized with mycelium. Key words: Mummy berry, stigma colonization, pseudosclerotium



2008 ◽  
Vol 56 (3) ◽  
pp. 241 ◽  
Author(s):  
Stella Kantartzi ◽  
D. G. Roupakias

Cotton breeders have long recognised the importance of alien germplasm from the Malvaceae family, especially the cultivated species, as sources of genes for cotton improvement. An understanding of the biological nature of the incompatibility systems that prevent hybridisation and/or seed development is necessary for the successful hybridisation and introgression between cotton and cultivated Malvaceae species (Hibiscus cannabinus and Abelmoschus esculentus). The objectives of the present study were to determine the reasons for reproductive isolation between Malvaceae species. The current study utilised two alien Malvaceae species and established that pollen–pistil incompatibilities are the primary reasons that hybrids with Gossypium hirsutum are not obtained. The alien pollen tubes showed major inhibition of growth in cotton pistils and seldom grew beyond the stigma. Only pollen tubes of A. esculentus grew into the ovary of cotton.



1995 ◽  
Vol 73 (4) ◽  
pp. 583-589 ◽  
Author(s):  
James A. Winsor ◽  
Andrew G. Stephenson

Pollen tube growth rates and pollen tube attrition were examined in Cucurbita pepo plants grown in an experimental garden. Two separate studies were performed utilizing controlled hand-pollinations. First, female flowers were hand-pollinated and collected at intervals over a 22-h period. Examination of stained pollen tubes in these pistils under reflected UV light revealed variation in growth rate: after approximately 7 h, the fastest growing pollen tubes grew at nearly twice the rate of the mass of the pollen tubes. The faster growing tubes reached the top of the ovary well ahead of most of the pollen tubes. Second, density of pollen application was varied and counts of germinated pollen and pollen tubes were made at four points from the stigmatic surface to the receptacle. Attrition was high for all pollen densities, but significantly higher rates occurred at high and medium densities just below the stigmatic surface. Pollen tube attrition at other points in the pistil was associated with constrictions in the stylar tissue and possibly with levels of nutrients in the pistil. Key words: Cucurbita pepo, pollen competition, pollen tube attrition.



2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Daisuke Tsugama ◽  
Tetsuo Takano

Abstract Objectives Pearl millet (Pennisetum glaucum) is a staple cereal crop for semi-arid regions. Its whole genome sequence and deduced putative gene sequences are available. However, the functions of many pearl millet genes are unknown. Situations are similar for other crop species such as garden asparagus (Asparagus officinalis), chickpea (Cicer arietinum) and Tartary buckwheat (Fagopyrum tataricum). The objective of the data presented here was to improve functional annotations of genes of pearl millet, garden asparagus, chickpea and Tartary buckwheat with gene annotations of model plants, to systematically provide such annotations as well as their sequences on a website, and thereby to promote genomics for those crops. Data description Sequences of genomes and transcripts of pearl millet, garden asparagus, chickpea and Tartary buckwheat were downloaded from a public database. These transcripts were associated with functional annotations of their Arabidopsis thaliana and rice (Oryza sativa) counterparts identified by BLASTX. Conserved domains in protein sequences of those species were identified by the HMMER scan with the Pfam database. The resulting data was deposited in the figshare repository and can be browsed on the Terse Genomics Interface for Developing Botany (TGIF-DB) website (http://webpark2116.sakura.ne.jp/rlgpr/).



1996 ◽  
Vol 121 (3) ◽  
pp. 419-422 ◽  
Author(s):  
Daiichiro Miyajima

The seed-producing system of salvias (Salvia splendens Sello) was investigated. The number of florets opening per day per plant increased with the increase in days from anthesis. Pollinators that effectively worked were small-sized insects. High pollen viability was observed on the stigmatic surface, and pollen tubes reached the ovules within 3 hours after pollination. Fertilized ovules became mature seeds within 25 days after fertilization. Pollination within 1 day after opening of florets resulted in a high percentage of seed setting. The pollen-ovule ratios indicated that salvias were facultative xenogamous. Actually, the salvias had heterostyle florets and the ability to set seeds without pollinators.



2018 ◽  
Author(s):  
Alex Harkess ◽  
Kun Huang ◽  
Ron van der Hulst ◽  
Bart Tissen ◽  
Jeffrey L Caplan ◽  
...  

The origin of sex chromosomes has been hypothesized to involve the linkage of factors with antagonistic effects on male and female function. Garden asparagus (Asparagus officinalis L.) is an ideal species to test this hypothesis, as the X and Y chromosomes are cytologically homomorphic and recently evolved from an ancestral autosome pair in association with a shift from hermaphroditism to dioecy. Mutagenesis screens paired with single-molecule fluorescence in situ hybridization (smFISH) directly implicate Y-specific genes that respectively suppress female organ development and are necessary for male gametophyte development. Comparison of contiguous X and Y chromosome shows that loss of recombination between the genes suppressing female function (SUPPRESSOR OF FEMALE FUNCTION, SOFF) and promoting male function (TAPETAL DEVELOPMENT AND FUNCTION 1, aspTDF1) is due to hemizygosity. We also experimentally demonstrate the function of aspTDF1. These finding provide direct evidence that sex chromosomes can evolve from autosomes via two sex determination genes: a dominant suppressor of femaleness and a promoter of maleness.



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