棉花诱导长柱头杂交制种及配套技术研究

旨在减少棉花杂交制种用工,提高棉花杂交制种工效,降低棉花杂交种子生产成本。采用GA₃溶液诱导棉花长柱头,不去雄直接授粉;采用小型强磁高速电动机作为动力,研制小型田间快速采粉器,同时研制与采粉器配套使用的简易授粉器。通过多年的研究,研制出一种新的杂交棉制种新方法,即用100 mg/kg浓度的GA₃溶液,处理8~18天母本的幼蕾,每花点滴量150~200 μL,开花当天,不去雄父本花粉直接授予母本伸长的柱头上;研制出与之相配套的棉花快速采粉器和低温贮能式授粉器,操作简便,田间采粉速度快,授粉效率高,生产的杂交种子纯度在95%以上,符合国家良种要求。该研究将稳定的诱导技术与采粉器和授粉器结合应用于棉花杂交制种,可节省大量用工,综合提高制种工效30%以上。     

Restrictions of the efficiency of haploid plant production in apple cultivar Idared,through parthenogenesisin situ

Summary For haploid plant production in Idared apple, parthenogenesisin situ was induced by irradiated pollen. The most important restrictions were seed set, embryo germination and green plant recovery from germinated embryos. The efficiency of green plant production was strongly influenced by irradiation dose, picking time and quality of the irradiated pollen. 250 Gy pollen was more efficient for green plant production than 500 Gy pollen. Using 250 Gy pollen with reduced germination capacity resulted in a five-fold lower green plant yield. Delaying picking of the fruits (140 instead of 70 days after pollination) had a significant positive effect. Up to 20 plants per 1000 pollinated flowers, showing no expression of a marker gene present in the pollen parent, were obtained in some treatments. Induction efficiency was high when seed weight was high. This offers the possibility of selecting seeds with the best chances for haploid plant production. Heavy seeds generally contained visual normal developed embryos, which germinated better than those from lighter seeds and gave normal plant development. Delayed picking increased the proportion of large seeds, suggesting that pollination with irradiated pollen retards embryo development. From treatments with irradiated pollen of poor quality more small seeds were harvested.     

Use of herbicide-resistant genic male sterility in hybrid rice seed production

One of the difficult problems in hybrid rice seed production is the low outcrossing frequency and requirement for much labor to produce hybrid seeds. In order to simplify the process of hybrid rice seed production, herbicide-resistant photoperiod sensitive genic male sterile (HRPGMS) rice was utilized in this study. The herbicide resistance gene bar was transferred into the photoperiod sensitive genic male sterile (PGMS) rice 920S by Agrobacterium-mediated transformation and the HRPGMS line YA3530ms with good agronomic characteristics was bred by applying conventional pedigree breeding technique. The seeds of HRPGMS and pollen parent were mixed with the ratio of 4:1 in weight, and were sowed in seedling box. The mixed seedlings of HRPGMS and pollen parent grown for 30 days were transplanted by the small transplanting machine in the field. The herbicide glufosinate ammonium was sprayed at 7 days after flowering to kill all the plants of pollen parent, whereas hybrid seeds were harvested from the survived HRPGMS parent at maturity. The outcrossing frequency of HRPGMS line from two combinations in 2002 and from five combinations in 2004 were compared with a control cultivated by the conventional 2-line system. As the result, the mean outcrossing frequency in HRPGMS of the treatments were 10.6–24.5% compared with 5.5% in PGMS of the control in 2002, and that were 24.7–32.0% compared with 7.5% in the control in 2004. Consequently, using HRPGMS in two-line system was proved to be a new method that would simplify the process of hybrid rice seed production and to increase outcrossing frequency without any artificial supplementary pollination processes.     

Heterosis in crop mutant crosses and production of high yielding lines using doubled haploid systems

Heterosis appearing in crosses between mutants derived from the same parent variety and crosses of mutants with parent varieties has been observed by many authors for many plant species including such important crops as barley, faba bean, maize, pea, pearl millet, rice, sunflower, sesame, sweet clover, triticale and wheat. Mutant heterosis was reported for crosses of spontaneous mutants, mutants obtained after treatment with various mutagens and recently also for somaclonal variants. The heterotic effects are usually related to an increase in some yield components. There is a lack of correlation between mutation of a particular plant character and appearance of heterotic effect. The yielding performance of a mutant was not correlated with its potential to give yield heterosis in crosses with another mutant, often also a very poor one, or with the parent variety. Poor yielding barley mutants from the collection of semi-dwarf forms of the Department of Genetics, Silesian University gave heterosis in crosses with other mutants or parent varieties for such characters as tillering, grain number and weight per plant. In addition to mutants with deleterious mutations of such characters as chlorophyll synthesis or fasciated stem there were also lines mutated for earliness, semi-dwarfness, low glucoside or high protein and lysine content which gave significant heterosis in crosses. One possible explanation of the phenomenon of mutant heterosis is related to the frequency of mutations induced by chemical and physical mutagens. The appearance and the level of heterotic effect of mutated genes will depend on their interaction with other mutated genes or with genes from the parental genotype. High specific combining ability of mutants giving heterotic effect makes hybrid seed production, based on crosses with defined sources of cytoplasmic or genetic male sterility, unfeasible or even impossible. Doubled haploids provide a unique system to attempt the ‘fixing’ of hybrid performance in homozygous lines and to avoid the step of hybrid seed production. The assumption on the ‘fixability’ of hybrid yield in homozygous lines based on reports that large additive genetic variance is responsible for yield heterosis in wheat or barley was proven also for mutant crosses. This revised version was published online in August 2006 with corrections to the Cover Date.     

小麦花药培养在春小麦群体改良中应用的初步研究

以太谷核不育基因为桥梁选用有关亲本组配了6个春小麦轮回选择集团,经轮选过一轮后,从中选择150个优良可育株,进行花药培养,其平均花药出愈率为22.09%,绿苗诱导率9.22%,均高于同年及上年度品种间杂交 F_1的花药培养结果。白苗分化率21.93%,与上述两年的 F_1培养结果相近。说明不育基因对花药培养无不良影响。加倍花粉植株二代     

Estimation of hybrid seed production and efficient pollen flow using insect pollination of male sterile soybeans in caged plots

The aptitude of leafcutter bees to pollinate male sterile soybean plants (ms2 gene) in caged plots was evaluated in four experiments from both quantitative and qualitative points of view. The m.s. plant seed set was satisfactory: on average, it represented 60% of the male fertile isogenic seed set (with a range between 44 and 69%). The lower yield of m.s. plants was linked with a smaller number of fertile reproductive nodes. The efficient pollen flow was observed over the flowering period with both morphological and electrophoretic markers. Insect behaviour was not influenced by flower colour. Differences between flowering duration of pollen donors appear to be the major factor inducing unbalanced populations. The interest of this technique as a tool for dynamic management of the genetic variation in populations or for hybrid seed production is discussed.     

Associations of some characters with seed yield in chickpea collections

Summary Three thousand two hundred and sixty-seven kabuli chickpea (Cicer arietinum L.) germplasm accessions were grown during the spring season of 1980 at Tel Hadya, the main research station of ICARDA, Syria to determine the components of seed yield. Observations were recorded on seed yield and 14 other characters. Correlation and path coefficient analyses were done to find out associations among characters and to assess the direct and indirect contribution of each character to seed yield.Large variation was observed for all the characters studied except days to flowering, days to maturity and protein content. Correlation and path coefficient analyses showed that biological yield and harvest index were the major direct contributors to seed yield. The 100-seed weight, plant height, days to flowering and maturity, canopy width, and protein content contributed to seed yield mainly through indirect effect via biological yield and harvest index. The 100-seed weight and seed yield were major contributors to biological yield. Major contributor to protein content was days to maturity. Results indicated that selection for high biological yield and harvest index would lead to high seed yield; and selection for large seed size would lead to high biological yield. Therefore, these characters should receive the highest priority in selecting high yielding plants in chickpea breeding.     

Geographical patterns of morphological variation in sorghum (Sorghum bicolor (L.) Moench) germplasm from Ethiopia and Eritrea: Quantitative characters

A total of 415 sorghum (Sorghum bicolor (L.) Moench) accessions representing different regions of Ethiopia, Eritrea and a group of introduced lines were evaluated for 15 quantitative characters to determine the extent and geographical pattern of morphological variation. The extent of variation was highly pronounced for agronomically important characters for sorghum. These characters included plant height, days for 50% flowering, peduncle exsertion, panicle length and width, number and length of primary branches per panicle and thousand seed weight. Significant regional variation was also observed for most of the characters. The results implied that environmental factors such as altitude, rainfall, temperature and growing period are important in regional variation. Mean for plant height and for days for 50% flowering showed clinal variation along the gradients of rainfall pattern and growing period in Ethiopia. Moreover, there were significant positive correlation coefficients between most of the characters. This included the correlation between agronomic characters of primary interest in sorghum breeding such as plant height and days for 50% flowering and also between various characters and the altitude of the collection sites. The implications of the results in plant breeding, germplasm collection and conservation as well as the probable sources of the wide range of variation are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Interaction between the eui gene and thermo-sensitive genic male sterility in rice

Panicle enclosure is a typical phenotype of almost all male-sterile rice lines. An elongated uppermost internode (eui) mutant exhibited notably rapid elongation of the uppermost internode at the heading stage; this is considered as a potential mechanism to eliminate panicle enclosure. We developed thermo-sensitive genic male-sterile (TGMS) eui mutants that were characterized by notably elongated uppermost internodes. The elongation of the uppermost internode in the TGMS eui mutant Changxuan 3S (CX) is mainly attributed to an increase in cell number and cell elongation, the latter being the more significant process. Temperature treatments revealed that the effects of temperature on panicle exsertion were similar to those on fertility and that the most temperature-sensitive stage coincides with the period from the formation of the pollen mother cell to meiosis during panicle initiation. These results indicate that elongation increases as temperature decreases and that the expression of the eui gene is more efficient at low temperatures than at high temperatures. In hybrid rice seed production using the TGMS eui mutant, the temperature range should be optimized at 24–28°C in order to preserve the development of completely male-sterile pollen and to eliminate panicle enclosure. Consequently, by using TGMS eui rice lines, gibberellin application can be avoided, thereby reducing the cost of hybrid seed production. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

杂交水稻秋制高产技术研究

针对杂交水稻秋季制种结实率低，父本花粉量少、活力弱、母本群体偏小等问题，实行“三项技改”，即改传统的小双行，小行比和拉绳赶粉为大双行、大行比和竹竿赶份，制种产量明显提高。     

‘隆科638S’与红颖恢复系‘先恢XK01’的混播制种效果初探

隐性红色颖壳资源是杂交水稻混播制种理想的遗传工具。为选育优质高产适用于混播制种的杂交新组合,本次研究探讨了‘隆科638S’与红颖恢复系‘先恢XK01’混播制种的产量影响因素。以‘隆科638S’为母本,红颖恢复系‘先恢XK01’为父本,基于正交设计法设计了3个因素：父本处理方式（抛秧和干处理）、播种方式（机械混直播、人工混撒播）、父母本比例(6:1、9:1、12:1、15:1),母本结实后进行小区测产,并通过五点法随机取5株样本考种,事后采用SPSS等软件进行数据分析。研究结果表明,‘隆科638S’与红颖恢复系‘先恢XK01’混播制种中父母本比例是影响产量的主要因素。最佳参数为机械成条形播、父母本比例(6:1)、父本抛秧播种,此时制种产量最高,为4157.85 kg/hm²,异交结实率为66.8%。初步得出结论该组合父母本花期相遇理想,产量高,异交结实率高,基本符合机械化制种的要求。本试验为机械化混播制种提供了数据参考。     

Some aspects of cross-pollination in wheat (Triticum aestivum L.) 1. Pollen concentration in the field as influenced by variety,diurnal pattern,weather conditions and level as compared to the height of the pollen donor

Summary For the large-scale production of hybrid seed the cross-fertilizing capacity of wheat must be increased. Breeding good pollinators is, therefore, a necessity. Five spring wheat varieties were examined for differences in pollen shedding capacity under normal field conditions. The examination was carried out by collecting pollen on object slides every hour from 06.00 till 20.00 h during flowering. In general, the variety Peko proved to be the best shedder of pollen, while Opal was the worst. Gaby, Jufy I and Orca were intermediate. Consistent results were hard to obtain mainly due to varying weather conditions.It was established that pollen is released throughout the whole period of daylight. The maximum release of pollen, however, occurred from 08.00 till 11.00 h. A less pronounced and much smaller peak was noticed from about 15.00 till 18.00 h. Most pollen appeared to be released at a temperature of 16–20°C and a relative humidity of 70–75%. Although there seems to be some relationship between the diurnal pattern of the pollen release and the indicated values of these meteorological factors, one cannot say that the former is entirely determined by the latter.It has been suggested in the literature that a male-sterile parent that is shorter than its pollinator would be most likely to produce good seed set in the hybrid wheat seed production field. Investigations showed that a greater concentration of pollen was found below the ear level of pollinator plants than at or above ear level.     

水稻籼爪交和粳爪交杂种优势的研究Ⅱ.农艺性状的杂种优势分析

研究了籼爪交和粳爪交杂种在长沙、三亚的农艺性状和干物质产量的杂种优势.在长沙的籼爪交杂种在结实率和每穗实粒数方面具有负向超亲优势,在每穗实粒数、结实率、单株粒重和理论产量方面存在负向对照优势,其余性状均为正向优势;粳爪交杂种在千粒重和结实率方面存在负向超亲优势,其余性状为正向超亲优势, 在始穗期、秆高和单     

A new method of producing 4x hybrid true potato seed

Summary New haploid-wild species hybrids (H-S) with desirable tuber type and 2n gamete production have been identified. They provide the opportunity for the production of inexpensive, 4x hybrid TPS from 2x×2x crosses. A proposed system to utilize plants producing either 2n eggs or 2n pollen is described. One H-S hybrid (female parent) would be selected for male fertility, self-incompatibility, high frequency of 2n eggs and no 2n pollen; an unrelated H-S (male parent) for male fertility and high 2n pollen production. In addition both parents would be selected for profuse flowering, attractiveness to bumblebees and other desirable characteristics. The male and female parents would be planted in alternate hills with bumblebees doing the pollinations. The elimination of emasculation, pollen collection, and hand pollination could reduce 4x hybrid TPS costs by more than 50 percent.     

Results of crossing Brassica pekinensis (Lour.) Rupr. with B. Oleracea L. Var. Acephala Dc.

Success in obtaining an interspecific hybrid between B. pekinensis and B. oleracea var. acephala was possible through the use of the Chinese cabbage as the seed parent and the use of the growth regulator, N-m-tolylphthalamic acid. The hybrids appeared vegetatively intermediate between the parents except for the inflorescence which appeared more like the kale parent. The F₁ was backcrossed with ease to the Chinese cabbage parent using the hybrid either as the pollen or seed parent. No backcross was made to the kale parent. Segregation in the F₂ was continuous for most characters studied.Michigan Agricultural Experiment Station, Journal Article Number 2588.     

In vitro mutagenesis induced novel thermo/photoperiod-sensitive genic male sterile indica rice with green-revertible xanthan leaf color marker

A series of leaf color mutants were isolated from young inflorescenceculture of thermo/photoperiod-sensitive genic male sterile (T/PGMS) indicarice `Xinguang S'. Most mutants maintained the temperature-insensitivityfor color expression, although some of the mutants weretemperature-sensitive and expressed the mutated colors only under higheror lower temperatures. One elite mutant `R172s' with a single recessivegene controlling green-revertible xanthan marker was found to possess thesame agronomic traits, combining ability, and T/PGMS characteristics as theoriginal parent. The marker-labeled seedlings were easily distinguished fromnormal green seedlings, and their survival rate under field conditions wassignificantly lower than that of hybrid seedlings. These results suggest thatthe leaf color mutations may be used as an ideal marker for monitoring theseed purity in hybrid rice production.     

Compatibility and incompatibility in witloof-chicory (Cichorium intybus L.). 1. The influence of temperature and plant age on pollen germination and seed production

Summary For the production of inbred lines and F₁ hybrids in witloof-chicory information is wanted on characteristics such as the incompatibility system. These characteristics can only be studied properly if the influence of temperature and physiological status of the plant on pollen germination and seed production is known. Investigations were carried out with 9 self-incompatible (SI) and 6 self-compatible (SC) clones in glasshouses of the IVT phytotron at constant temperatures of 10, 14, 17, 20, 23 and 26°C. In general, in vivo pollen germination percentages were rather low after self pollination with an optimum for germination around 17–20°C. No seeds were formed at the lowest temperature (10°C) while seed production for SC clones was usually (rather) good at higher temperatures. At 26°C seed production in some clones decreased. Both pollen germination and seed production decreased at the end of the flowering period. There was a rather positive relationship at e.g. 17 and 20°C between pollen germination after selfing and seed production. When no pollen germination was observed, no seed formation occurred. When pollen grains did germinate, seed development would not necessarily occur in all cases. So this relationship only enables negative mass selection for SC.     

An intersubgeneric hybrid between Glycine tomentella Hayata and the soybean,G. max (L.) Merr.

Summary The objective of the present paper is to provide information on the morphology and cytology of an intersub-generic hybrid (2n=59) between Glycine tomentella Hayata (2n=78) and G. max (L.) Merr. (2n=40) obtained through in vitro immature seed culture. The hybrid plant was slow in vegetative growth and twinning like the female parent but morphologically was intermediate between both parents for several traits. At metaphase I, the average chromosome associations and ranges for 25 cells were 44.0 I (37–51)+7.5 II (3–11). The plant was completely pollen and seed sterile. The present investigation suggests that wild perennial Glycine species can be exploited as either the male or female parent in wide hybridization programs with the soybean, G. max.     

Modified complementation test of male sterility mutants in pepper (Capsicum annuum L.): preliminary study to convert male sterility system from GMS to CMS

The male sterility system in hybrid seed production can eliminate the cost of emasculation and ensure seed hybridity through avoidance of self pollination. GMS and CMS are two types of male sterility system that currently employed in pepper breeding. Conversion from GMS to CMS will increase the male sterility proportion of female parent from 50 to 100%. In this study, segregation analysis of four male sterile mutants consisting of one CMS mutant (CA1) and three GMS mutants (GA1, GA3 and GA4) showed that each had single recessive gene inheritance. A modified complementation test was performed by replacing male sterile mutants with their maintainer line as male parent. The nuclear restorer gene for CMS was independent of all nuclear restorer genes for GMS and all nuclear restorer genes for GMS were independent each other. Further observation on CMS and GMS male sterility loci revealed that GA1 and GA3 had mutated in both nuclear restorer genes for CMS and GMS, while CA1 and GA4 each carried mutation in single male sterility system of nuclear restorer gene for CMS and GMS, respectively. Conversion from GMS to CMS in the case of lines carried mutations in both sterility systems required only S-type cytoplasm donor, while lines carried mutation in single nuclear restorer gene for GMS required not only S-type cytoplasm but also rf allele donors. The important finding is the broader function of maintainer line in certain male sterility system that can be used as a maintainer or restorer line for other male sterility systems. We also confirmed that line CC1 is the general restorer for both CMS and GMS systems.     

Interspecific hybridization between rice bean (Vigna umbellata) and its wild relative (V. minima): Fertility-sterility relationships

Summary The pre-and post-fertilization barriers in the interspecific crosses between Vigna umbellata and V. minima were investigated. In the reciprocal crosses (V. minima as the parent) the entry of pollen tubes into the ovary was delayed by about 4 h, and no seed set was observed. However, no pre-fertilization barriers were encountered in crosses involving V. minima as the parent and V. umbellata as the parent (normal cross). The delay/absence of divisions in the endosperm and the failure of embryo to divide were the post-fertilization barriers responsible for somatoplastic sterility in normal crosses which yielded a few hybrid seeds. The hybrid seeds showed poor germinability. The F₁ hybrids were intermediate between the parents in most morphological characters, and are completely sterile for pollen. Backcrossing of F₁ hybrid with both the parents did not restore fertility in the progenies. V. minima is considered as the tertiary gene pool of the rice bean.