Semi-sterile Plants Research Articles

The changes of economically valuable signs got under the influence of gamma-ryes

Relevance. The plants treated and modified under the influence of a physical mutagen of the Co60 isotope at doses of 500, 1000, 5000, 10000, 20000 and 30000 r were grouped into types. Changes in such economically valuable features as yield per one bush, fiber yield, weight of raw cotton in one boll and fiber length under the influence of the Co60 isotope in experimental optionss were studied. With an increase in the dose of gamma rays, an increase in fiber yield was observed. In the AzNIHI-195 variety, when exposed to a lower dose of gamma rays (500 R) on seeds before sowing, the fiber yield was 35.9%, at a high dose (30,000 R) — 37.2%. Fiber yield varies depending not only on the variety, but also on the placement of the bolls on the bush. Forms with short and long fibers selected according to various options are of particular importance as a starting material and on their basis, in the next generation, it is possible to select forms with long fibers. The resulting economically valuable forms will be used as starting material in breeding work.Methods. The research studied the change in the mass of raw cotton of one boll under the influence of gamma rays on seeds. The results of the impact of gamma rays on the seeds of varieties AzNIKHI-104 and AzNIKHI-195 in M 1 shows a change in the mass of raw cotton in one boll. On this basis, sharp differences were obtained both in the effect of different doses of gamma rays among themselves, and in comparison with the control option. In the variety AzNIKHI-104 in M1, the obtained differences were at the ranges of 0.2–0.9 gr. At a high concentration of mutagens, a sharp change in the average weight of one boll was observed.Results. In both varieties, an increase in the dose of the mutagen leads to an increase in both the mass and the yield of raw cotton fiber, while the yield of raw cotton in one bush decreases. When exposed to high doses, low-yielding, semi-sterile and sterile plants are obtained, and the length of the fiber increases at low doses. A similar result is observed in both cotton varieties.

Expression of kenaf mitochondrial chimeric genes HM184 causes male sterility in transgenic tobacco plants

Chimeric genes resulting from the rearrangement of a mitochondrial genome were generally thought to be a causal factor in the occurrence of cytoplasmic male sterility (CMS). In the study, earlier we reported that identifying a 47 bp deletion at 3′- flanking of atp9 that was linked to male sterile cytoplasm in kenaf. The truncated fragment was fused with atp9, a mitochondrial transit signal (MTS) and/or GFP, comprised two chimeric genes MTS-HM184-GFP and MTS-HM184. The plant expression vector pBI121 containing chimeric genes were then introduced to tobacco plants by Agrobacterium-mediated T-DNA transformation. The result showed that certain transgenic plants were male sterility or semi-sterility, while some were not. The expression analysis further demonstrated that higher level of expression were showed in the sterility plants, while no expression or less expression in fertility plants, the levels of expression of semi-sterility were in between. And the sterile plant (containing MTS-HM184-GFP) had abnormal anther produced malformed/shriveled pollen grains stained negative that failed to germinate (0%), the corresponding fruits was shrunken, the semi-sterile plants having normal anther shape produced about 10–50% normal pollen grains, the corresponding fruits were not full, and the germination rate was 58%. Meanwhile these transgenic plants which altered on fertility were further analyzed in phenotype. As a result, the metamorphosis leaves were observed in the seedling stage, the plant height of transgenic plants was shorter than wild type. The growth duration of transgenic tobacco was delayed 30–45 days compared to the wild type. The copy numbers of target genes of transgenic tobacco were analyzed using the real-time quantitative method. The results showed that these transgenic plants targeting-expression in mitochondrial containing MTS-HM184-GFP had 1 copy and 2 copies, the other two plants containing MTS-HM184 both had 3 copies, but 0 copy in wild type. In summary, the two manual chimeric genes might be related to male sterility in kenaf.

Cytological Observation of Anther Development of Photoperiod/Thermo-sensitive Male Sterile Line Huiyou50S in Brassica napus

A photoperiod/thermo-sensitive male sterile line, named Huiyou50S, was developed from a spontaneous semi-sterile plant found in Brassica napus cultivar Huiyou50. The male sterility of Huiyou50S was controlled by recessive nuclear genes. Huiyou50S presents male sterile under high temperature and long photoperiod condition, and fertility under low temperature and short photoperiod. The cytological characters of pollen and the anther development of Huiyou50S at the different stages were compared with its near isogenic line Huiyou50F, which is the male fertile sibling, by techniques including semi-thin sections, scan electronic microscopy, pollen grains staining with aceto-carmine, and whole anther clearing with methyl salicylate. The result indicated that the anther development of Huiyou50S was similar to that of Huiyou50F from sporogenous cell, pollen mother cell, meiosis, to tetrad stage. At the uni-nucleate stage, although the exine formed, the protoplast of microspores condensed, and the cell became empty. At last all cellular content of pollen degraded completely and only the empty and distorted shell remained. The tapetum development of Huiyou50S was similar to that of Huiyou50F up to tetrad stage, but its tapetal cells rapidly disintegrated at the uni-nucleate stage, which occurred earlier than that in Huiyou50F, while the tapetum of Huiyou50F did not degenerate at this stage. In conclusion, the microspores of Huiyou50S abort mainly at the uni-nucleate stage, and there are some associations between pollen abortion and tapetal cells’ disintegration. This result is helpful to classification and utility of photoperiod/thermo- sensitive genic male sterility.

Genetic and cytological analyses of the male sterility mutation induced in a sorghum tissue culture with streptomycin

Treatment of sorghum callus cultures with 500-1000 mg/l streptomycin led to a high regeneration frequency of plants with complete or partial male sterility (MS), up to 100% of all green regenerants. The induced MS mutation (ms-str) was preserved in the F1 and BC1 progenies and was genetically unstable: many families produced semisterile and fertile revertants, whose progenies again contained semisterile and sterile mutants. The ms-str mutation was maintained through eight generations via selection and self-pollination of semisterile plants. The mutation was inherited as a recessive nuclear mutation in tester crosses of sterile plants segregated in the progenies of fertile and semisterile revertants and was expressed only in single cases in a test cross for ms-str transfer through pollen of hybrids with restored male fertility. Recessive nuclear mutations determining a low plant height (dwarfness) and the lack of waxy bloom on the stem and leaves (bloomless) were found in male-sterile plants with the ms-str mutation. Cytological analysis of sterile plants reveal multiple alterations of various pollen development stages and tapetal cells: cytomyxis, defects of chromosome conjugation, distorted cytokinesis in meiotic division II, a lack of tetrad separation, a defective formation of the microspore coat, generation of microspores with two to four nuclei, and the formation of micronuclei and large vacuoles in tapetal cells. A possible transfer of the induced cytoplasmic MS mutation into the nuclear genome and the causes of the high genetic instability are discussed.

Fine mapping of pss1, a pollen semi-sterile gene in rice (Oryza sativa L.)

During routine seed increase procedures in rice, semi-sterile plants are common; however, such semi-sterility mutants in rice varieties have been only rarely analyzed genetically. W207-2 is a semi-sterile selection from the japonica rice variety Nipponbare. In this report, we found the female gamete of W207-2 was normal, and its semi-sterility was unaffected by growth duration but was conditioned by a recessive nuclear gene whose action leads to pollen semi-sterility and anther indehiscence, and the gene was named as pss1 (pollen semi-sterile). Using an F(2) population derived from the two parents W207-2 and Dular and a pooled DNA strategy, pss1 was mapped to an interval on chromosome 8 defined by the two SSR loci RM6356 and RS41. The position of pss1 was confirmed in another F(2) population derived from the cross W207-2 x Nipponbare. Over 2,000 homozygous pss1 segregants from the large W207-2 x Dular F(2) population were used to fine map pss1 to a 0.04 cM segment flanked by a CAPs marker L2 and a dCAPs L3 marker. Sequences for both markers are present on a single PAC clone, and the physical distance between them is about 28 kb. Analysis of the PAC sequence predicts the presence of five open reading frames, they are as follows: putative ribonuclease PH, putative avr9 elicitor response protein, kinesin1-like protein, putative protein RNP-D precursor and putative 40S ribosomal protein S13. This result would be helpful in cloning the pss1 gene.

Localization and fine mapping of gaMS-1 , a male gametophytic mutant of maize

Post-meiotic mutants affecting pollen development are fundamental tools for defining the genetic program controlling microsporogenesis and pollen function. An example of such mutants is gametophytic male sterile-1 (gaMS-1). Heterozygous plants gaMS-1/+ that have a normal phenotype and are female fertile, segregate 1:1 normal:sterile pollen grains and their selfed progeny segregates 1:1 normal:semi-sterile plants. With the final aim of isolating the gene, a positional cloning strategy was adopted. In this paper, we report the results of fine mapping GaMS-1 by different types of molecular markers. Two back crosses were used as mapping populations. They were obtained by crossing the line carrying the mutation with the inbred lines Mo17 and WF9, used as recurrent male parents. Linkage disequilibrium analysis allowed assigning GaMS-1 to the short arm of chromosome 2.By the combined use of SSR, AFLP, PCR markers and ESTs a region of 1 cM containing GaMS-1 was delimited.

The Location of Genes Governing Long First Internode of Corn

Knowing breeding behavior and cytological location of traits helps breeders. My objective was to locate dominant genes for long first internode of corn (Zea mays L.). I determined that Hopi Indian corn PI213733 (variety Komona) displayed the trait and grew well in the U.S. Corn Belt. I crossed PI213733 to 26 translocation tester stocks in Minnesota inbred A188 background, backcrossed semi-sterile plants carrying the translocation to A188 the next generation, and grew the segregating generation planted in trenches 15 cm deep with ridges of dirt 10 cm high one year, in trenches 25 cm deep the other year and also at normal (6 cm) depth. Emerged plants were classified for semi-sterility or for normal pollen. I concluded from multiple testers for each chromosome arm that dominant genes for long first internode are located (chromosome and region) on 3S, on 6 near the centromere, and on 9S; spurious associations occurred for two testers. Measurement of cell lengths indicated that PI213733 had more cells than A188 both in upper and in lower mesocotyl sections and that lower, older cells elongated sooner. I found a normal-sized kernel with twin embryos that developed two long first internode seedlings indicating that the amount of endosperm did not limit mesocotyl growth.

CHARACTERIZATION OF SOMACLONAL VARIATION IN TISSUE CULTURE-DERIVED TANGERINE-VIRESCENT LINES OF TOMATO

The tangerine-virescent (tv) mutation was reported as a single gene somaclonal variant from tissue culture (Evans and Sharp 1963). A replicated field trial was conducted to characterize variation and stability in the phenotype of this tv somaclone and to compare it with the inbred parent from which it was reportedly derived.Heritability and stability of the tv somaclonal variant was measured by comparing R3 end R4 lines of sexual progenies of the original tv variant and with its sexually derived inbred parent UC82B. Several additional variants were observed in these tv lines, including fruit shape, days to first flower, fruit weight, yield, plant type, and fertility. Eight sterile or semi-sterile plants were discovered in 6 of 39 R4 lines. Our results suggest that multiple genetic changes have occurred in the tv somaclonal variant and while the original tv mutant is stably inherited, additional genetic abnormalities occur following sexual reproduction.

Intraspecific differentiation of Setaria italica (L.) P.B.: study of abnormalities (weakness, segregation distortion, and partial sterility) observed in F1 and F2 generations

Hybrid weakness, segregation distortion, and partial sterility were observed in the offspring of Setaria italica (L.) P.B. following intraspecific crosses. These perturbations occurred in hybrids involving strains from two different geographical origins (China and Europe). However, the parental lines were morphologically similar. In this study, the F1 and F2 generations arising from crosses between Chinese and French varieties were analysed. We hypothesized that the genetic determination of weakness may be due to two complementary recessive genes. The segregation distortion for Adh isozyme could be due to a selection on one type of gamete. Partial sterility was also studied. No meiotic perturbation was observed in semisterile plants, but the tapetal cells were abnormal. The study of F2 generations suggests that the sterility is controlled by a few major genes.Key words: foxtail millet, intraspecific sterility, F2 weakness, segregation distortion, genetic differentiation.

Pollen irradiation and gene transfer in Capsicum

The aim of the experiment was to study the possibility of facilitating the gene transfer and reducing the number of required backcrosses through pollen irradiation and subsequent selection of F1M1 plants containing a very high proportion of sterile pollen as male parent for backcrossing. Anthers of a donor line, C-3-1, were irradiated with 1,500 rad γ-rays and the pollen used for pollination of a recipient genotype W-8 which posseses a number of recessive marker genes. Five F1M2 plants containing more than 80% sterile pollen grains and one semi-sterile plant were selected and used for backcross to W-8. The segregation pattern of four characters expressed in the first backcross generation [W-8×(W-8×C-3-1)] was assessed and compared with the non-irradiated control. A changed segregation pattern was observed (in some cases even non-transfer of a paternal allele) as well as a shift towards more plants possessing the investigated maternal alleles. A scheme for backcross procedure in combination with pollen irradiation is discussed.

Cytoplasmic male sterility in Vicia faba L.

In many higher plants, nucleo-cytoplasmic interactions lead to pollen abortion. In Vicia faba, cytoplasmic male sterility is unstable as the cytoplasm appears to shift from a sterile to a fertile state. In this report, five flower phenotypes are defined but the study is focussed on the progenies obtained from intermediate, semi-sterile plants with the same homozygous nuclear constitution during five successive generations. The results could be interpreted by quantitative modifications of at least four different kinds of cytoplasmic determinants.

Genic Male Sterility in the Common Bean (Phaseolus vulgaris L.)1

Abstract A male sterile bean plant was observed in the F2 population of WI 74-2047 × ‘Swedish Brown’. Male sterile phenotypes were characterized by all pollen grains being shriveled and non-functional, but with female fertility unaffected. Expression of sterility was genic, involving 2 unlinked loci, Ms1 and In-ms1, which interact to give a 13:2:1 F2 ratio of non-sterile:sterile:lethal individuals. ‘Swedish Brown’ contained fully fertile and semisterile plants, the latter presumed to be caused by the presence of a reciprocal translocation. One of the loci involved in male sterility is loosely linked to one of the break points of the translocation, and lines segregating for sterility but not semisterility were obtained.

Inheritance and Linkage Studies of Cytoplasmic Male Sterility and Monogermity in Sugar Beets

Annual multigerm and monogerm pollen restorer lines (P-MM and P-mm), which, were isolated from the cross combination of the annual multigerm (cytoplasmic) male sterile and biennial monogerm strain both introduced from USA, were crossed with annual multigerm and monogerm male sterile lines (TA-1-MS and TA-2-MS). F1 and F2 populations of the cross combination of TA-2-MSXP-mm and TA-1-MSXP-MM were grown and checked for two characters, male sterility and monogermity, at the Yamagata University (Tsuruoka) during the summer of 1972, 1973 and 1974. This study confirmed that monogermity was governed by recessive monogenic inheritance, although monogerm plants in F2 Segregation were slightly fewer than the expected value. Pollen parent lines and F1 populations segregated no complete sterile plants, but considerably produced semisterile plants besides complete fertile plants. The appearance of semi-sterile types was attributable to effects of environment and minor modifying genes in the interaction with two major genes. The mode of inheritance applied to the pollen parent lines used in this study was as follows : Using the Owen's gene scheme, complete sterility and semi-sterility are governed by only X gene locus and complete sterility is induced by the single recessive condition, whereas pollen fertility is controlled by the complementary effect of X and Z genes. This will support Owen's original hypothesis. In addition to this gene scheme, minor modifying genes accelarate or suppress male sterility. Linkage relation between one pollen restorer gene, X, and monogerm gene was not recognized in this cross combinations. In linkage relation between the other pollen restorer gene, Z, and monogerm gene, there were some cases of the significant inter-action between the two genes, which was responsible for segregations as if the F2 had been in a coupling phase of linkage notwithstanding a repulsion phase. This suggests that Z gene locus was independent of monogerm gene.

Gamma Radiation Effects on Pearl Millet Pollen1

Gamma irradiation of pollen from pearl millet [Pennisetum americanum (L.) K. Schum. (formerly P. typhoides)] inbreds at doses of 0.2 to 16 kR indicated, based on seed set, that inbreds ‘Tift 23DB’ and ‘Tilt 186’ were significantly more sensitive to irradiation than inbred ‘Tift 239DB.’ Average seed set obtained by irradiating pollen of these inbreds was reduced about 50% at doses between 1.2 and 3 kR. No seed set was obtained when pollen was irradiated at 16 kR. Pollen irradiated at 3 kR produced the highest frequency (11%) of semisterile plants. Seed set on semisterile plants (generally 20 to 60%) was adequate to make the translocations useful cytological stocks.

Chromosomal rearrangements in Plantago insularis Eastw.

Seeds of Plantago insularisEastw. which were irradiated with gamma rays yielded 37–67% semi-sterile plants. Twenty-four out of sixty-four of these plants were heterozygous for one or more chromosomal rearrangements. Twothirds of these were translocations, and one-third were inversions. Homozygous lines for four translocations were established. The karyotypes of these provide chromosome markers either at pachynema or in mitotic divisions, or both.

Reciprocal translocations induced by x-rays and thermo-neutrons in wild Sorghum (S. purpureo-sericeum Aschers and Schweinf.).

Dry seeds of S. purpureo-sericeum were irradiated with either X-rays or thermo-neutrons with three exposures each. No difference was shown in germination between the irradiated treatments and the control. The percentage of survival was greatly reduced to 2.2% in seeds treated with X-rays. However, there was no significant difference in survival between the thermo-neutron treatments and the control. Both radiation treatments inhibited seedling height to a considerable degree, and the variability of seedling height increased with higher exposures of irradiation. The types and the frequency of induced interchanges were proportional to the exposure of thermo-neutron irradiations.Twenty six translocation heterozygous plants were analyzed and considered to be semisterile plants. Spore quartet analysis revealed that the two types of adjacent segregations occur with nearly the same frequency.Six plants with pseudo-isochromosomes were detected. Pseudo-isochromosomes were often delayed in anaphase movement. They were excluded from daughter nuclei at telophase stages and eventually became micronuclei in the spore quartets.Two plants with a ring-of-six, and one plant with two pseudo-isochromosomes plus a ring-of-six were also found among the materials irradiated with high exposures of thermo-neutrons. Pollen counts showed that they had the lowest fertility among translocation heterozygous plants and no seed was obtained.

Bulk staining of ovules and ovaries to note the percentage of well-organized embryo sacs in sterile and semi-sterile plants utilized for breeding purpose

La maculation massive des ovaires et ovules d'Oryza sativa L. a été faite avec du vert rapide et de alcool:xylol (1:1) par étapes. Après section il fut possible de noter le pourcentage des sacs embryonnaires viables et non-viables plus particulièrement dans des plantes stériles et semistériles. Ce procédé peut donner aux planteurs des directives dans leurs expériences d'élevage. Il a permi aussi de localiser les phases exactes de l'avortement.

Spontaneous Reciprocal Translocation during Megasporogenesis of Maize Haploids

IN the course of an investigation of haploidy in maize, a number of haploids were pollinated by normal diploid males. The progenies were grown to anthesis and classified for pollen abortion, with the thought that some of them would be monosomic, that is, would arise from n-1 eggs. An F1 plant was found to be semi-sterile (male) and was self-pollinated and outcrossed with a normal female. Subsequent examination of the selfed and outcrossed progenies revealed that the original semi-sterile F1 plant was heterozygous for a reciprocal translocation. The finding agrees with earlier observations in which recovery of reciprocal translocation from haploids of Triticum vulgare1 and of Sorghum vulgare2 had been made.

RECIPROCAL TRANSLOCATIONS IN SORGHUM VULGARE

Endrizzi and hilorgan ( 1955) reported the occurrence of reciprocal translocations in Sorghz~77jl m ~ l g a r e but did not examine pachynema configurations. The present study deals with cytological observations at prophase of meiosis, including pachynema, of three reciprocal translocations obtained by Haensel (1960) after gamma irradiation of the reactive grain sorghum variety Experimental 3 . Seedlings of this genotype are transformed, after colchicine treatment under certain conditions (Franzlte et al., 1960), into either true breeding or segregating mutants. Materials and Methods At preanthesis stage, panicles of S. wz~ lgnre , variety Experimental 3 a true breeding dwarf grain type sorghum, whose origin has been previously described (Franzlte and Ross, 1952), were subjected to irradiation with cobalt 60 under different dosages by Haensel (1960). Three reciprocal translocations, designated as T165, T23 1 and T396, were identified in semi-sterile plants of progenies from these panicles. Pollen was examined by dissecting individual anthers in a lacto-phenol-acid fuchsin stain conlposed of 20 cc. of phenol, 20 cc. of lactic acid, 40 cc. of glycerin, 20 cc. of water and 8 cc. of I % acid fuchsin. This stain was observed to give the same results as IKI. About 500 pollen grains from each plant were examined in randomly selected microscope fields. Under greenhouse conditions, tlle percentage of viable pollen of normal Experimental 3 varied from 80-97%. T o identify plants l~omozygous for the translocation within the progeny of a heterozygous plant, those having 80% or more viable pollen were hand enlasculated and crossed to normal Experimental 3. Examination of the percentage of pollen abortion of tlle plants growing from these seeds identified plants hoinozygous for the translocation. Plants which showed about 50% ~ o l l e n abortion \vere classified as heterozv~ous for the translocation and were I J U transplanted to the field in the spring for study of meiosis. Heads talten fro111 these materials grown in the field were fixed in 3 ethyl alcohol: 1 glacial acid and stored in 70% ethyl alco1~ol. Chromosomes were stained with propionic carmine. hl~easureineks of chromosomes in translocation confi~u;ations at '3 pacl~ynenla kvere made from enlarged photographs. Results Cytological exan~inations of translocation configurations of the homozygous normal and homozygous reciprocal translocation lines at pachynema, dialtinesis, and metaphase I stages showed no irregularities. Differing proportions of rings and chain configurations in plants heterozygous for the translocations were observed, as shown in Table I. T396 followed by T231 have the largest proportions of chain configurations. The nucleolus cl~romoson~e was found to be involved in translocation T396. Per cent pollen viability is shown in Table I1 for plants obtained by selfing the translocation heterozygotes. The fertile plants showed some pollen abortion while the semisterile plants, l~eterozygous for the translocations, had means of 42.7% to 49.4% viable pollen.

Behaviour of an extra-fragment chromosome induced by Bassia oil inZea mays

Maize plants raised from seeds soaked in Bassia oil frequently produced semi-sterile ears. In one case the progeny of a semi-sterile plant consisted of (1) plants with the normal number of bivalents and (2) plants with a fragment chromosome in addition to the normal number. The behaviour of the extrafragment chromosome in meiosis has been studied in detail. The origin of the fragment chromosome is also discussed. It is regarded as formed by fragmentation of a normal chromosome. This is possible on account of the frequent occurrence of fragmentation and other structural chromosome alterations in maize plants raised from seeds soaked in Bassia oil. A kernel loss of about 25% has been observed in plants having an extra-fragment chromosome. There was no evidence of an effective mechanism for progressive numerical increase of the fragment chromosome. Instead it was found that there is a significant loss of the extra-fragment chromosome from one generation to another.