Chromosome numbers, pollen fertility, and pollen size in Haworthia species and hybrids

1973 ◽  
Vol 51 (10) ◽  
pp. 1753-1759 ◽  
Author(s):  
S. K. Majumdar ◽  
H. P. Riley
Keyword(s):  
Chromosome Numbers ◽  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
Diploid Species ◽  
Pollen Sterility ◽  
Statistical Analyses ◽  
Pollen Size ◽  
Tetraploid Level

Sporophytic chromosome numbers were determined for 216 species, varieties, or hybrids of the genus Haworthia. There were 152 diploids (2n = 14), 10 triploids, 38 tetraploids, 7 pentaploids, 7 hexaploids, and 2 aneuploids. Among the species studied, most of the diploids were highly fertile. The tetraploids were somewhat less so, the triploids were generally less than 50% fertile, and the pentaploids and hexaploids were generally intermediate between the diploids and the triploids. The few diploid interspecific hybrids were less fertile than the diploid species. Each additional set of chromosomes increased the pollen size, and this increment was found to be significant up to the tetraploid level. Statistical analyses of comparisons between pollen size means of the hexaploids and pentaploids, and of the pentaploids and tetraploids were not significant. Pollen sterility is interesting in connection with the problem of speciation in the Aloineae, which is discussed.

Study of the possibilities of using sunflower lines with different colours of seeds to create poultry feed

Helia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Katerina Vedmedeva ◽  
Tatiana Machova
Keyword(s):  
Pollen Fertility ◽  
Animal Feed ◽  
Fertility Restoration ◽  
Emerging Market ◽  
Pollen Sterility ◽  
Wild Birds ◽  
Hybrid Breeding ◽  
Poultry Feed ◽  
Human Consumption ◽  
Seed Colour

Abstract Sunflower is used for the production of oil, confectionery and animal feed. Birds are very fond of sunflowers and can be pests of sunflower crops, and are consumers of seeds. Sunflower poultry feed is an emerging market that determines the direction of breeding. Its development is based on the determination of bird preferences and the available variety of sunflower lines. This is what our research is devoted to. Experimental feeding of chickens with a mixture of sunflower seeds of different colours was carried out. Chickens have been found to prefer contrasting striped seeds with white and dark stripes more than others. The white colour of the seeds was eaten less than others. Studies of the genetics of sunflower colour allow us to distinguish two groups of lines by seed colour. The first has white seeds with the EwEwPP genotype, suitable for use in human confectionery and more protected from being eaten by wild birds in the fields. The second is striped seeds with the EstrEstrPP genotype, which can be fed whole seeds to birds. Donors of seed colour traits and other traits important for hybrid breeding were selected from the evaluated collection of sunflower lines. InK1039 line is a donor of small striped seeds and pollen fertility restoration. InK1587 line is a sterility fixer and donor of striped and early maturing seeds. To create hybrids with white seeds for human consumption and thus more resistant to ingestion by wild birds, white seed donors were isolated with KG9 to restore pollen fertility and I2K2218 in a pollen sterility fixer.

CHROMOSOME NUMBER, VOLUME AND NUCLEAR VOLUME RELATIONSHIPS IN A POLYPLOID SERIES (2X-20X) OF THE GENUS RUMEX

1971 ◽  
Vol 13 (4) ◽  
pp. 842-863 ◽  
Author(s):  
S. Ichikawa ◽  
A. H. Sparrow ◽  
C. Frankton ◽  
Anne F. Nauman ◽  
E. B. Smith ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Abrupt Change ◽  
Diploid Species ◽  
Nuclear Volume ◽  
Polyploid Series ◽  
Unidentified Species

Ninety-one acquisitions of the genus Rumex obtained from various sources were examined taxonomically and cytologically. These acquisitions included 36 species plus 2 unidentified species. The chromosome numbers counted were 2n = 14 (or 15), 16, 18, 20, 40, 42, 60, 80, 100, 120, 140, 160, ca. 170, 180 and ca. 200. The count of 2n = 180 made on one of the R. orbiculatus acquisitions is a new count for this genus, but other acquisitions had 160 and ca. 170. First counts were obtained for four species, R. frutescens (2n = 160), R. crystallinus (2n = 60), R. cristatus (2n = 80) and R. tenax (2n = 80). The count of 2n = 160 for R. frutescens is the highest chromosome number ever reported in the section Axillares. The chromosome numbers determined in R. palustris (2n = 60), R. confertus (2n = 100), R. arcticus (2n = 120) and R. aquaticus (2n = 140) differ from previously published counts. Our counts for eight other species support one of the previous counts where two or more counts are reported. It is shown that the species of the subgenus Acetosa sections Acetosa and Vesicarii and of the subgenus Platypodium have relatively large chromosomes, those of the subgenus Acetosa section Scutati and of the subgenus Acetosella have medium-sized chromosomes, and the members of the subgenus Rumex sections Axillares and Rumex have smaller chromosomes. The chromosomes of the diploid species of the section Rumex were larger than those of the polyploids (4x to 20x) of the same section. Within the section Rumex the log of nuclear volume increased with increasing ploidy, with an abrupt change (decrease) in slope between the 12x and 14x levels.

Evidence for genetic suppression of heterogenetic chromosome pairing in polyploidy species of Solanum, sect. Petota

1983 ◽  
Vol 25 (5) ◽  
pp. 530-539 ◽  
Author(s):  
Jan Dvořák
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Diploid Species ◽  
Diploid Hybrid ◽  
Polyploid Species ◽  
Chromosome Differentiation ◽  
Genetic Suppression ◽  
Solanum Sect ◽  
Paradoxical Results

Data on chromosome pairing in haploids and interspecific hybrids of Solanum, sect. Petota reported in the literature were used to determine whether the diploidlike chromosome pairing that occurs in some of the polyploid species of the section is regulated by the genotype or brought about by some other mechanism. The following trends emerged from these data. Most of the polyploid × polyploid hybrids had high numbers of univalents, which seemed to indicate that the polyploid species were constructed from diverse genomes. Haploids, except for those derived from S. tuberosum, had incomplete chromosome pairing. All hybrids from diploid × diploid crosses had more or less regular chromosome pairing, which suggested that all investigated diploid species have the same genome. Likewise, hybrids from polyploid × diploid crosses had high levels of chromosome pairing. These paradoxical results are best explained if it is assumed that (i) the genotypes of most polyploid species, but not those of the diploid species, suppress heterogenetic pairing, (ii) that nonstructural chromosome differentiation is present among the genomes of both diploid and polyploid species, and (iii) the presence of the genome of a diploid species in a polyploid × diploid hybrid results in promotion of heterogenetic pairing. It is, therefore, concluded that heterogenetic pairing in most of the polyploid species is genetically suppressed.

Evidence for the presence of an intercontinental genome in the Australian hexaploid alliance of Hibiscus Sect. Furcaria

1980 ◽  
Vol 28 (3) ◽  
pp. 369 ◽  
Author(s):  
MY Menzel ◽  
DW Martin
Keyword(s):  
Sri Lanka ◽  
South America ◽  
Interspecific Hybrids ◽  
New World ◽  
Hawaiian Islands ◽  
Diploid Species ◽  
Australian Species ◽  
Data Support ◽  
North And South America ◽  
North And South

Genomes of the G group in Hibiscus sect. Furcaria have been found previously in one African diploid species and in various ailoploid combinations in Africa, India and Sri Lanka, North and South America and the Hawaiian Islands. Study of 11 interspecific hybrids between the Australian species H. heterophyllus and H. splendens and G-genome testers indicates that genomes somewhat related to the G group are present in the Australian allohexaploid alliance. These genomes are designated G′. Several of the intercontinental hybrids studied were weak, inviable or morphologically abnormal. The data support the interpretation that the genomes of the Australian alliance have diverged more from African and New World genomes than the latter two have from each other.

New chromosome numbers for rutaceae

1992 ◽  
Vol 5 (4) ◽  
pp. 501 ◽  
Author(s):  
HM Stace ◽  
JA Armstrong
Keyword(s):  
Chromosome Numbers ◽  
Pollen Sterility ◽  
Chromosome Counts ◽  
Cytological Data ◽  
Taxonomic Implications

Chromosome counts for 30 taxa, representing five genera, are reported for Rutaceae subfamily Rutoideae, mostly in the Australasian tribe Boronieae. We found n = 10 for Boronia algida which is previously unreported in the genus, and a sterile triploid taxon in Zieria. Generic chromosome numbers of n = 18 in Zieria, n = 16 in Phebalium and n = 14 in Eriostemon sens. lat. occur, while Boronia shows cytoevolution on n = 18, 11, 10, 9. Pollen sterility and possible apomixis is indicated in some species. Some taxonomic implications of cytological data in the tribe Boronieae are discussed.

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  

scholarly journals Interspecific hybridization between diploid Fagopyrum esculentum and tetraploid F. homotropicum

2005 ◽  
Vol 85 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Yingjie Wang ◽  
Rachael Scarth ◽  
Clayton Campbell
Keyword(s):  
Interspecific Hybridization ◽  
Chromosome Numbers ◽  
Dna Analysis ◽  
Genetic Recombination ◽  
Diploid Species ◽  
Normal Growth ◽  
Colchicine Treatment ◽  
Chromosome Elimination ◽  
Ploidy Levels

The wild diploid species Fagopyrum homotropicum (2n = 2x = 16) has been used for buckwheat improvement, but, prior to this study, the tetraploid form (2n = 4x = 32) had not been hybridized with the cultivated species F. esculentum. The objective of this study was to hybridize F. esculentum with tetraploid F. homotropicum to increase the genetic variability. Forty-one interspecific F1 hybrids were obtained through ovule rescue in vitro, with hybridity confirmed using morphological characters, chromosome numbers (2n = 3x = 24) and DNA analysis. The F1 plants were mainly sterile. However, seven seeds were set spontaneously on two hybrid plants, and a large number of seeds were obtained after colchicine treatment. The F2 plants were divided into two groups based on chromosome numbers and morphology. The first group was hexaploid plants (2n = 6x = 48) or hypohexaploid plants (2n = 44–46), partially fertile with “gigas” features including increased height, dark green leaves, and large seeds with thick seed hulls. The second group of plants was diploid (2n = 2x = 16) (one plant had 17 chromosomes), with normal growth and fertility, and a combination of characters from both parents, indicating that genetic recombination had occurred during chromosome elimination. The diploid group was superior to the hexaploid group for use in buckwheat breeding programs due to the desirable characters and the ease of crossing. This is the first report of interspecific hybridization using different ploidy levels in the Fagopyrum genus. Key words: Buckwheat (F. esculentum; F. homotropicum), interspecific hybridization, breeding, tetraploid, diploid, hexaploid, fertility

Cytoplasmic male sterility in Desmodium

1969 ◽  
Vol 20 (2) ◽  
pp. 227 ◽  
Author(s):  
KS McWhirter
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Interspecific Hybrid ◽  
Pollen Fertility ◽  
Pollen Sterility ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Male Sterile ◽  
Genetic Stocks

A type of male sterility found in two Desmodium plants of probably interspecific hybrid origin was cytoplasmically inherited. The cytoplasmic male-sterile character was incorporated in the tropical legume Desmodium sandwicense by backcrossing. In this genetic background pollen sterility was complete. The male-sterile character was not graft-transmissible, and it produced no detectable pleiotropic effects on growth and development. Desmodium intortum gave restoration of pollen fertility in Fl hybrids with male-sterile lines of D. sandwicense. Restored F1 hybrids produced apparently normal pollen, but tests of functional ability of the pollen disclosed that pollen fertility was less than that of Fl hybrids with normal cytoplasm. Incomplete restoration of fertility was not due to heterozygosity of fertility-restoring genes with gametophytic expression, since fertility-restoring genes were shown to act sporophytically. The results established the occurrence in the legume Desmodium of a system of determination of the male-sterile, fertility-restored phenotypes that is similar to the cytoplasmic male sterility systems described in many other angiosperm plants. A scheme utilizing the genetic stocks produced in this study for commercial production of the interspecific hybrid D. sandwicense x D. intortum as a cultivar is presented.

Breeding behavior and chromosome numbers among New Guinea and Java Impatiens species, cultivated varieties, and their interspecific hybrids

1974 ◽  
Vol 52 (5) ◽  
pp. 923-925 ◽  
Author(s):  
Allan R. Beck ◽  
Jack L. Weigle ◽  
Eric W. Kruger
Keyword(s):  
Chromosome Numbers ◽  
Interspecific Hybrids ◽  
New Guinea ◽  
Chromosome Morphology ◽  
Breeding Behavior ◽  
Chromosome Counts

Impatiens crosses were made among the following: P.I. 349629 (Java), P.I. 349586 (New Guinea), I. Itolstii, and "Tangerine." All crosses were successful except those made with I. Itolstii. Chromosome counts were as follows: P.I. 349629 = 16, P.I. 349586 = 32, I. Itolstii = 16, and "Tangerine" = 8. Chromosome counts of the hybrids were midway between the respective parents. Cytological studies indicated a similarity in chromosome morphology and size among all parents except I. holslii. A new genome count of 4 is reported for the genus Impatiens indicating a ploidy series in which x = 4.

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