DESYNAPSIS IN SOME DIPLOID AND POLYPLOID SPECIES OF ALLIUM

1971 ◽  
Vol 13 (4) ◽  
pp. 723-728 ◽  
Author(s):  
R. N. Gohil ◽  
A. K. Koul
Keyword(s):  
Chromosome Numbers ◽  
Allium Sativum ◽  
Pollen Grains ◽  
Polyploid Species ◽  
Male Sterile

Desynapsis has been reported in two diploid (Allium sativum and A. consanguineum) and one tecraploid (A. tuberosum) species of Allium. The desynaptic A. sativum is totally male sterile. A. consanguineum is a medium-strong, and A. tuberosum a weak desynaptic. Desynapsis in the latter two species upsets the course of meiosis and results in pollen grains with varying chromosome numbers and considerably reduced fertility.

scholarly journals Construction of a weight-based seed sorting system for the third-generation hybrid rice

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jianxin Wu ◽  
Shijun Qiu ◽  
Menglong Wang ◽  
Chunjue Xu ◽  
Xing Wang Deng ◽  
...  
Keyword(s):  
Hybrid Rice ◽  
Pollen Grains ◽  
Third Generation ◽  
Male Sterile ◽  
Specific Expression ◽  
The Third ◽  
Genes Encoding ◽  
Wild Type Male ◽  
Sorting System ◽  
Generation Hybrid

Abstract Background The third-generation hybrid rice technology can be constructed by transforming a recessive nuclear male sterile (NMS) mutant with a transgenic cassette containing three functional modules: the wild type male fertility gene to restore the fertility of the mutant, the pollen killer gene that specifically kills the pollen grains carrying the transgene, and the red fluorescence protein (RFP) gene to mark the transgenic seed (maintainer). The transgenic plant produces 1:1 NMS seeds and maintainer seeds that can be distinguished by the RFP signal. However, the RFP signals in the partially filled or pathogen-infected maintainer seeds are often too weak to be detected by RFP-based seed sorting machine, resulting in intermingling of the maintainer seeds with NMS seeds. Results Here we constructed a weight-based seed sorting system for the third-generation hybrid rice technology by silencing the genes encoding ADP-glucose pyrophosphorylase (AGP) essential for endosperm starch biosynthesis via endosperm-specific expression of artificial microRNAs (amiRNAs). In this system, the NMS seeds have normal endosperm and are heavy, but the maintainer seeds have shrunken endosperms and are light-weighted. The maintainer seeds can be easily and accurately sorted out from the NMS seeds by weight-sorting machines, so pure and fully filled NMS seeds are available. Conclusions The weight-based seed sorting system shows obvious advantages over the RFP-based seed sorting system in accuracy, efficiency, and cost for propagation of pure male sterile seeds. These characteristics will significantly increase the value and transgenic safety of the third-generation hybrid rice technology.

A natural intergeneric hybrid of Gesneriaceae from Brazil

Phytotaxa ◽  
2021 ◽  
Vol 497 (2) ◽  
pp. 79-96
Author(s):  
ANDRÉA ONOFRE DE ARAUJO ◽  
MAURO PEIXOTO ◽  
CINTIA NEVES DE SOUZA ◽  
EDUARDO CUSTÓDIO GASPARINO ◽  
JULIANA TOLEDO FARIA ◽  
...  
Keyword(s):  
Chromosome Numbers ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Intergeneric Hybrid ◽  
Morphological Characters ◽  
Natural Hybrid ◽  
Pollen Data ◽  
Cytological Data ◽  
High Viability ◽  
Structural Abnormalities

A natural hybrid between Goyazia and Mandirola (Gloxiniinae, Gesneriaceae) from Cerrado (Brazil) is here described, supported by pollen morphology, cytological data and morphological characters. The microsporogenesis of Mandirola hirsuta and that of the hybrid were analyzed in order to evaluate the cytogenetic characteristics. The haploid chromosome numbers observed were n = 12 for M. hirsuta and n = 11, 13, 16 and 26 for the hybrid. Structural abnormalities (monads, dyads, triads and micronuclei) were observed at the final of the hybrid’s meiosis. High viability rates of the pollen were recorded for Goyazia and Mandirola (>90%) and low viability for the hybrid (34.7%). The pollen grains were acetolyzed, measured and photographed for pollen morphology analysis. Quantitative pollen data were analyzed through descriptive and multivariate statistics. The hybrid has intermediate pollen characteristics between G. petraea and M. hirsuta; it is more related to G. petraea by the measures of diameters and ectoapertures; it is more similar to M. hirsuta mainly regarding the microreticulum on the mesocolpium region. The hybrid and Mandirola share vegetative and flower size, while the colors of the hybrid are similar to Goyazia. Pollen morphology, cytological data and morphological characters brought clear evidence for the recognition of the intergeneric hybrid, which we named as Goydirola x punctata.

scholarly journals Relationship between pollen morphology and chromosome numbers in Brazilian species of Lippia L. (Verbenaceae)

2013 ◽  
Vol 85 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Saulo M. Sousa ◽  
Patrícia M.O. Pierre ◽  
Giovana A. Torres ◽  
Lisete C. Davide ◽  
Lyderson F. Viccini
Keyword(s):  
Chromosome Numbers ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Positive Association ◽  
Single Species ◽  
Morphological Data ◽  
Prolate Spheroidal ◽  
Oblate Spheroidal ◽  
Exine Ornamentation ◽  
Different Types

The pollen morphology and exine structure of 17 species of Lippia L. were investigated in this work using light and scanning electron microscopy. Among the species studied, 14 showed tricolporate pollen grains, two had tri- and tetracolporate pollen grains and a single species exhibited, only tetracolporate pollen. The amb ranged from triangular to square, and the shape varied from oblate-spheroidal to prolate-spheroidal. Three different types of exine ornamentation were observed: psilate, scabrate and perforate. In addition to morphological data, we found positive association between the chromosome numbers and size of pollen grains, and also between the length and width of the colpi. The results indicate that the characteristics of pollen grains in Lippia may be used as an additional taxonomic character of the genus.

scholarly journals Reproductive characterization of interspecific hybrids among Capsicum species

2011 ◽  
Vol 11 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Carlos Eduardo da Silva Monteiro ◽  
Telma Nair Santana Pereira ◽  
Karina Pereira de Campos
Keyword(s):  
Male Sterility ◽  
Interspecific Hybrids ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Male Sterile ◽  
Viable Pollen ◽  
Hybrid Combination ◽  
Capsicum Species ◽  
The Cross

The objective of this study was the reproductive characterization of Capsicum accessions as well as of interspecific hybrids, based on pollen viability. Hybrids were obtained between Capsicum species. Pollen viability was high in most accessions, indicating that meiosis is normal, resulting in viable pollen grains. The pollen viability of species C. pubescens was the lowest (27 %). The interspecific hybrids had varying degrees of pollen viability, from fertile combinations (C. chinense x C. frutescens and C. annuum x C. baccatum) to male sterile combinations. Pollen viability also varied within the hybrid combination according to accessions used in the cross. Results indicate that male sterility is one of the incompatibility barriers among Capsicum species since hybrids can be established, but may be male sterile.

scholarly journals Two New Isomers of Palmityl-4-hydroxycinnamate from Flowers of Taraxacum Species

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Matej Dudáš ◽  
Mária Vilková ◽  
Tibor Béres ◽  
Miroslav Repčák ◽  
Pavol Mártonfi
Keyword(s):  
Nmr Spectroscopy ◽  
Pollen Grains ◽  
2D Nmr ◽  
Male Sterile ◽  
2D Nmr Spectroscopy ◽  
First Time

Two isomers, (Z)- and (E)-palmityl 4-hydroxycinnamate [hexadecyl(2Z)-3-(4-hydroxyphenyl)prop-2-enoate and hexadecyl(2E)-3-(4-hydroxyphenyl)prop-2-enoate] were isolated for the first time from ligulate flowers of Taraxacum linearisquameum Soest (sect. Taraxacum). The highest amount of these compounds was detected in pollen grains; 0.26 mg/100 mg DW of the (E)-isomer and 0.096 mg/100 mg DW of the (Z)-isomer. The structures of these compounds were elucidated by a combination of HPLC-ESI-Qtof-MS and ID and 2D NMR spectroscopy. Their presence was confirmed in other species of Taraxacum, but they were not found in the male-sterile triploid agamospermous taxon T. parnassicum.

Chromosomal Differentiation Among Ecotypes of Phalaris aquatica L.

1980 ◽  
Vol 28 (6) ◽  
pp. 645 ◽  
Author(s):  
E Putievsky ◽  
RN Oram ◽  
K Malafant
Keyword(s):  
Pollen Grains ◽  
F1 Hybrids ◽  
Male Sterile ◽  
Geographic Origins ◽  
Meiotic Irregularities ◽  
Structural Differences ◽  
Two Generations ◽  
Chromosomal Differentiation ◽  
Mother Cells ◽  
F2 Progeny

Seventy-two hybrids of P. aquatica were made among 13 diverse Mediterranean ecotypes and cv. Australian, and five indicators of hybrid abnormality were measured in the first two generations. The proportions of stainable, apparently normal pollen grains formed by F, hybrids varied between 5 and 98% and their spikelet fertility ranged from 19 to 77%. Of the 43 hybrids that were derived from pairs of self-incompatible parents, 13 were highly self-compatible. Crosses between lines from different groups of parents produced F2 progeny containing up to 17% of lethal seedlings and up to 39% of male sterile plants. In the cross between cv. Australian and the Moroccan ecotype, CPI 19331: the frequency ofzebra-striped lethal seedlings was as high as 33% in F2 progenies, but only 0 or 1% in back-crosses to either parent. Hence the zebra-striped phenotype was not caused by a mutation existing in the parents but rather by deletions or duplications generated during meiosis in the F1 hybrids. Many meiotic irregularities were observed in the pollen mother cells of the F1 and F2 hybrids between cv. Australian and CPI 19331. These included small loops, acentric fragments, univalents and multivalents at diakinesis, and bridges at anaphase I, indicating that the genomes of these two lines differed by several inversions and interchanges. These structural differences would lead to a range of duplications and deficiencies in the gametes. and hence could account for each of the five kinds of hybrid abnormality observed in the F1 and F2 generations. One aneuploid F2 plant with 25 chromosomes was found. A dihaploid plant in cv. Australian had an average of 4.3 bivalents per pollen mother cell, whereas virtually all chromosomes in the tetraploid parental lines paired as bivalents. Thus, P. aquatica is a segmental allotetraploid with a system which prevents homoeologous pairing in tetraploids but not in dihaploids. The partial barriers to hybridization between P. aquatica lines are not closely related to their geographic origins or varietal classifications. These barriers may hinder but have not prevented the recombination of parental traits during the development of improved cultivars.

scholarly journals Pollen and Spikelet Analysis in F1 Rice Hybrids and their Parents

2014 ◽  
Vol 8 ◽  
pp. 120-126 ◽  
Author(s):  
Bal K. Joshi ◽  
Laxmi P. Subedi ◽  
Santa B. Gurung ◽  
Ram C. Sharma
Keyword(s):  
Pollen Fertility ◽  
Practical Importance ◽  
Pollen Grains ◽  
Gene Interaction ◽  
Pollen Sterility ◽  
Spikelet Fertility ◽  
High Fertility ◽  
Male Sterile ◽  
Pollen Abortion ◽  
Spikelet Sterility

Pollen analysis can be used to discriminate between different species, identify possible  interspecies hybrids, identify restorer and maintainer lines, useful to study genetics of  restorer gene, interaction between chromosome and cytoplasm and relationship between  parents. Pollen abortion system of male sterility is an important tool in hybrid rice  production and spikelet is the major yield components. Nine improved cultivars, six  landraces and three wild aborted cytoplasmic-genetic male sterile (CMS) lines were used to  analyze pollen and spikelet in F1 rice hybrids and their parents. The frequency of pollen  categories and its relationship to spikelet fertility were investigated. Pollen sterility of the  F1s was determined by staining pollen grains in 1% potassium iodide-iodine (I-KI) solution.  Spikelet fertility was determined by counting the total number of seed set in proportion to  the total number of spikelets. Correlation and regression coefficients for some traits were  computed. In hybrids, pollen fertility ranged from 0.5 to 82% and spikelet fertility from 0 to  87%. Pollen fertility varied from 28 to 97%, while spikelet fertility from 73 to 91% in pollen  parents. The highest and the lowest percentages of pollen fertility were found in Chaite-6  and Chiunde cultivars respectively. Spikelet fertility percentage varied widely among  hybrids and many hybrids had lower spikelet fertility percentage than their parents.  Therefore, it is of practical importance to understand the causes of high spikelet sterility in  hybrids for possible increase in spikelet fertility. Highly significant positive correlation was  found between stained round fertile (SRF) pollen and spikelet fertility. The positive value of  correlation and regression coefficient on SRF and spikelet fertility were found between F1  and mid parent, and F1 and male parent. High fertility of cross may be due to the presence of  a wide compatibility gene or restorer genes in the cultivar. Lower pollen and spikelet  fertility of the crosses was attributed to effect of the genetic background of the tester parent. Nepal Agric. Res. J. Vol. 8, 2007, pp. 120-126 DOI: http://dx.doi.org/10.3126/narj.v8i0.11605  

STUDIES ON THE FAILURE OF HYBRID GERM CELLS TO FUNCTION IN WHEAT SPECIES CROSSES

1932 ◽  
Vol 6 (4) ◽  
pp. 362-373 ◽  
Author(s):  
W. P. Thompson ◽  
J. M. Armstrong
Keyword(s):  
Germ Cells ◽  
Chromosome Numbers ◽  
Pollen Grains ◽  
Wheat Species ◽  
Experimental Conditions ◽  
Degree Of Reduction ◽  
Random Segregation ◽  
Nuclear Development

Chromosome numbers were determined in numerous male gametophytes of F1 between 21- and 14-chromosome species of wheat. The results show that pollen grains with various chromosome numbers from 14 to 21 are actually formed and in approximately the theoretically expected proportions. The lack of plants in later generations which should result from the functioning of pollen grains with intermediate numbers is therefore not due to the failure of such grains to be formed because of a lack of random segregation at the second reduction division.Grains with intermediate numbers are retarded in their nuclear development, so that counts made on stamens in which division is most active give a smaller proportion of grains with intermediate numbers and a higher proportion with parental numbers than is expected theoretically. Retardation in nuclear development is correlated with a deficiency in cytoplasmic contents, 10 to 15% of the grains showing little or no cytoplasm, and another 15 or 20% showing some degree of reduction in cytoplasm. AH grains with reduced cytoplasm and some of those with normal contents are so retarded in nuclear development (having only one or two nuclei or no organized male cells) that they could not function when the normal ones are mature and the stamen dehisces. Unfavorable chromosome conditions in grains with intermediate numbers cause a complete abortion of some grains and retardation of nuclear development in others.Under the best available experimental conditions only 11 or 12% of F1 pollen grains germinate, in contrast to 70 or 80% for parental pollen. No grains with reduced cytoplasm germinate, and at least 50% of those with apparently normal cytoplasm fail to germinate.

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 Anatomical Characteristics of Petalized Anther Abortion in Male Sterile Camellia oleifera Plants

2021 ◽  
pp. 1-13
Author(s):  
Yang Hu ◽  
Chao Gao ◽  
Quanen Deng ◽  
Jie Qiu ◽  
Hongli Wei ◽  
...  
Keyword(s):  
Germination Rate ◽  
Pollen Grains ◽  
Relative Activity ◽  
Control Group ◽  
Camellia Oleifera ◽  
Male Sterile ◽  
Flower Bud ◽  
Triphenyltetrazolium Chloride ◽  
Pollen Sacs

Petalized anther abortion is an important characteristic of male sterility in plants. The male sterile plants (HB-21) evincing petalized anther abortion previously discovered in a clone population of the Camellia oleifera cultivar Huashuo by our research group were selected as the experimental material in this study. Using plant microscopy and anatomic methods and given the correspondence between external morphology and internal structure, we studied the anatomic characteristics of petalized anther abortion (with a fertile plant as the control group) in various stages, from flower bud differentiation to anther maturity, in hopes of providing a theoretical basis for research on and applications of male sterile C. oleifera plants, a new method for the selection of male sterile C. oleifera cultivars, and improvements in the yield and quality of C. oleifera. In this study, the development of anthers in C. oleifera was divided into 14 stages. Petalized anther abortion in male sterile plants was mainly initiated in the second stage (the stage of sporogenous cells). Either the petalized upper anther parts did not form pollen sacs, or the entire anthers did not form pollen sacs. The lower parts of some anthers could form deformed pollen sacs and develop, and these anthers could be roughly divided into two types: fully and partially petalized anthers. Abnormal callose and the premature degradation of the tapetum occurred in the pollen sacs formed by partially petalized anthers during the development process, resulting in the absence of inclusions in the pollen grains formed. Small quantities of mature pollen grains withered inward from the germinal furrows, exhibiting obvious abortion characteristics. The relative in vitro germination rate of the pollen produced by the partially petalized anthers of sterile plants was 11.20%, and the relative activity of triphenyltetrazolium chloride was 3.24%, while the fully petalized anthers did not generate pollen grains. Either the petalized anthers in male sterile plants did not produce pollen, or the vitality of the small amounts of pollen produced by sterile plants was very low compared with that of fertile plants. Such male sterile plants could be used to select correct clones and have good prospects for application in production.

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