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1.
T. Hodgkin 《Euphytica》1980,29(1):65-71
Summary In a study of partial self-compatibility in Brassica oleracea, flower number, seeded siliqua and seed production were recorded on self-and cross-pollinated inflorescences of the progenies of a half diallel between six in bred Brussels sprout plants homozygous for the same moderately recessive incompatibility allele S45.On both self-and cross-pollinated inflorescences significant amounts of additively controlled genetic variation were found for seed set per flower. For cross-pollinated inflorescences this was also the case for the two components of seed set, seeded siliquae per flower and seeds per seeded siliquae, but for self-pollinated ones only seeded siliquae production showed significant additive variation. Considerable heterosis and gene interaction were always present and a simple additive dominance model did not explain the variation.Two of the parents transmitted lower levels of partial self-compatibility to their progenies and, in one of these, dominant genes appeared to be responsible. The most important feature determining the production of self seeds was found to be the number of flowering sites at which the incompatibility mechanism failed rather than the number of seeds produced at each site.  相似文献   

2.
Summary In 1974 and 1975 gametocidal effects of Ethrel were investigated under field conditions in the spring wheat cv. Zlatka. In experimental plants grain setting per spikelet and ear as well as ability to be cross-pollinated were ascertained.As compared with the control, treated variants achieved more than 90% sterility. Female fertility was not affected and cross-pollination was possible. Genetical check showed that the best variants, when cross-pollinated, produced 50–55% hybrids; grain setting, however, was brought down by more than 37%. As a result of Ethrel treatment haulm length was reduced and the vegetation period was somewhat prolonged.  相似文献   

3.
Intergeneric hybrid plants between Colchicaceous ornamental plants, Sandersonia aurantiaca and Gloriosa rothschildiana, have successfully been produced via ovule culture. After 5 days of reciprocal cross-pollination, a few pollen tubes were observed in the ovary. Although seeds were obtained in both reciprocal cross-combinations, they did not germinate under ex vitro conditions. Ovules with placental tissues isolated 14 days after cross-pollination of S. aurantiaca × G. rothschildiana were cultured on a medium containing 0.01 mg l–1 each of -naphthaleneacetic acid (NAA) and 6-benzyladenine (BA), on which 41.5% of ovules swollen and produced callus-like structures within 10 weeks. When such swollen ovules were transferred to a medium containing 0.1 mg l–1 each of NAA and BA, 7.5% of the initially cultured ovules produced rhizome-like structures within 6 weeks. Among the rhizome-like structures, those derived from two independent ovules (3.7% of the initially cultured ovules) produced multiple shoots following transfer to a medium containing 0.25 mg l–1 NAA and 2.5 mg l–1 BA. Multiple shoot-derived plantlets were established on a plant growth regulator-free medium, and they were successfully transplanted to pots. Early verification of their hybridity was accomplished by flow cytometry (FCM) analysis, chromosome observation and rDNA analysis.  相似文献   

4.
Summary The impact of cross pollination 30 h, 4 h, and immediately prior to self-pollination, and self-pollination 2, 4, 8, 12, 24 and 30 h prior to cross-pollination was assessed for pollen tube number per style, seed number per siliqua, and proportion of self-seed (sibs) per siliqua, in two inbred lines of brussels sprout. Pollination procedure had a marked effect on the amount of sib-and hybrid seed produced. Cross pollination 30 h prior to self-pollination produced significantly greater numbers of sib progeny, as did self-pollination 8–12 h before cross pollination. Prior application of self pollen reduces the number of pollen tubes in the style. The results of this experiment suggest that self-incompatibility in brussels sprout could better be assessed by self-pollination with a subsequent cross pollination 8 h later, and the determination of amounts of sib and F1 hybrid seed per siliqua.  相似文献   

5.
Effect of high temperature on incompatibility in radish   总被引：1，自引：0，他引：1  
Summary Clones of radish plants were cross-pollinated or selfed at 17 and 26 °C. In crosscompatible plants the fruit set; the average number of seeds per fruit and the total seed yield were decreased at 26 °C. In incompatible plants the fruit set and the total seed yield were increased when selfing was done at the higher temperature. It is concluded that while high temperature has an unfavourable effect on seed set of radish plants, it also weakens the incompatibility reaction between pollen and style, so that the result is a small increase in yield.  相似文献   

6.
A. H. Eenink 《Euphytica》1981,30(1):71-76
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.  相似文献   

7.
Vaccinium elliottii Chapmn., a diploid blueberry in Vacciniumsection Cyanococcus, was crossed with V. arboreum Marsh, a diploid blueberry insection Batodendron. The goal was toproduce hybrids that could be used toincorporate traits from these species intotetraploid southern highbush cultivars. The crosses were made reciprocally usingtwo clones of each species. A recessiveseedling marker gene for anthocyanin-freecotyledons in the V. elliottii clonesused as female parents permitted thetesting of mentor pollination. For thementor pollinations, V. elliottiiplants that were homozygous for therecessive marker allele were pollinatedwith a small amount of viable V.elliottii pollen carrying the recessivemarker mixed with a large amount of V.arboreum pollen carrying the dominantmarker. Thousands of intersectional hybridseedlings were obtained when V.elliottii was the seed parent, both withand without mentor pollination, but nohybrids were obtained from 2735 flowerspollinated in the reciprocal crosses. Theseeds that gave rise to hybrid embryos weresmaller than normal V. elliottiiseeds, but germinated well. Hybridseedlings grew slowly at first, buteventually produced some vigorous plants inthe field, although many plants remainedmuch smaller than normal seedlings of thetwo parental species. Some of the hybridsproduced numerous flowers during the 6years they were observed in the field, buteven with many diploid, tetraploid, andhexaploid section Cyanococcus blueberryplants growing nearby that could haveprovided pollen for their flowers, thehybrids produced no viable seed.  相似文献   

8.
Blueberry (Vaccinium section Cyanococcus, family Ericaceae) is a shrub that produces multiple-seeded berries in which only a fraction of the ovules develop into viable seeds. A recessive yellowleaf marker gene was used to evaluate the efectiveness of a single pollination versus multiple pollinations in producing seeds in Vaccinium elliottii Chapm. A multiple-pollination experiment was conducted to see if the first pollen applied or the second produced more progeny, and to see if multiple pollinations increased the number of seedlings produced. Flowers of diploid yellowleaf Vaccinium elliottii were pollinated from one to four times at daily intervals. Pollen from redleaf and yellowleaf plants was used to produce two types of seedlings that could be distinguished visually. Generally, percent berry set, seeds per berry, and seed germination were not increased by multiple pollination. After multiple pollination, the pollen applied first always produced the most seedlings. Prior pollination greatly reduced seed set from subsequent pollination, but subsequent pollination caused little or no decrease in the number of seeds set by the first pollination. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
V. K. Gupta  S. Gudu 《Euphytica》1991,52(1):33-38
Summary Phylogenetic relations among the three species in grain amaranth need investigation to provide information for breeding experiments germplasm conservation efforts, and decision on evolutionary patterns in the grain types. Hybrid development from crosses between species was studied to find out genetic relationship between them. Interspecific crosses were made among Amaranthus hypochondriacus, A. caudatus and A. cruentus in the glasshouse. The F1 plants were relatively easy to obtain but had low pollen fertility (10.3–15.1%) and low seed set. A few of these hybrids did not produce seeds. Only a few F1 seeds obtained in crosses between A. cruentus and A. caudatus. All the F1 plants from these crosses died at the seedling stage. Crosses between A. cruentus and A. hypochondriacus produced few seeds. Most of the F1 plants obtained from the seeds died at the seedling stage with only four plants growing to maturity but were sterile. Based on hybrid development, it was suggested that A. hypochondriacus and A. caudatus were genetically closer than the other two combinations of species studied. A. cruentus seemed to be genetically closer to A. hypochondriacus than it was to A. caudatus.Research was supported by Grand No. AMA-KE-4-83-22. (CRG GRANT) from the National Academy of Science, U.S.A.  相似文献   

10.
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.  相似文献   

11.
Linked leaf rust and stripe rust resistance genes introduced from Triticum dicoccoides protected common wheat seedlings against a range of pathotypes of the respective pathogens. The genes were chromosomally mapped using monosomic and telosomic analyses, C-banding and RFLPs. The data indicated that an introgressed region is located on wheat chromosome arm 6BS. The introgressed region did not pair with the ‘Chinese Spring’ 6BS arm during meiosis possibly as a result of reduced homology, but appeared to pair with 6BS of W84-17 (57% of pollen mother cells) and ‘Avocet S’. The introgressed region had a very strong preferential pollen transmission (0.96–0.98) whereas its transmission through egg cells (0.41–0.66) varied with the genetic background of the heterozygote. Homozygous resistant plants had a normal phenotype, were fertile and produced plump seeds. Symbols Lr53 and Yr35 are proposed to designate the respective genes.  相似文献   

12.
Summary Flatpea (Lathyrus sylvestris L.) is a potentially valuable forage legume, but it contains high levels of 2,4-diaminobutyric acid (A2bu), a compound that can have adverse effects on some animals, including rats and poultry. This study evaluated intercrossed pollination methodology needed for cultivar improvement and characterized intercrossed progeny for A2bu concentration. Pollen germination on an artificial medium, using pollen collected during different stages of flower development, was used to identify appropriate stages for flower emasculation. Pollen dehiscence occurred at an early-bud stage when petal color was first evident. Slightly more mature buds contained pollen with substantially higher in vitro germination than pollen from early-bud stage flowers. Lines that produced high numbers of seeds per pollination were identified from crosses between flatpea accessions. Cross-pollination resulted in significantly higher seed set than selfing. Pollination using caged honeybees was the most efficient method of hybridization, although the degree of inbreeding in bee-pollinated plants could not be determined. Intercrossed progeny produced by honeybee pollination contained a lower mean concentration of foliar A2bu than the mean for flatpea accessions.Abbreviations HPLC high performance liquid chromatography - OPA ortho-phthalaldehyde  相似文献   

13.
Summary An autotetraploid population of caraway (Carum carvi L.) was produced by treating the growing points of young plants with a 0.2% colchicine solution. Selection on morphology, pollen size and pollen shape, followed by a selection on seed size proved to be an effective way to identify the mixoploid C0 plants. Three percent of the treated plants produced a tetraploid progeny. Moderate selection in the C1 and the C2 population resulted in an improvement of the average seed-set to the amount of 50% of the diploid control, with a range of 21–78%. The 1000-kernel weight of the tetraploid material was 7 g, compared to 3 g in the diploid control. The oil content of the autotetraploid seed was increased with 35.6%; the increase in carvone amounted to 6.9%. The results of the experiment indicate that breeding work in autotetraploid caraway may result in a new cultivar.  相似文献   

14.
N. G. Hogenboom 《Euphytica》1972,21(2):228-243
Summary Attempts were made to break the self-incompatibility in L. peruvianum by selection of mutated S-alleles through large-scale self-pollination on clones with pollen which was mutagenically treated in different stages of development. Besides self-compatibility was searched for in inbred lines.The self-incompatibility in L. peruvianum was found to be very strict indeed. From more than 22,000 self-pollinations on 5 clones 1527 seeds were obtained, seed set being very erratic. The possible causes of this seed set are discussed. From 1527 seeds 1036 plants were raised and tested for self-compatibility.In the progenies of 4 clones from 823 plants tested, 7 were more or less self-compatible. It is concluded that this self-compatibility was spontaneous and not the result of the mutagenic treatment.In the progeny of the fifth clone plants were found which reacted as self-compatible at a temperature of about 40°C and as self-incompatible at lower temperatures. It is suggested that this character—a high temperature sensitive incompatibility reaction—is governed by one recessive gene.In inbred lines plants were found with a stable form of self-compatibility and also plants with a high temperature sensitive incompatibility reaction.The problems of an incompatibility research on inbred material are discussed. A brief survey is given of some of the characters found in inbred L. peruvianum.  相似文献   

15.
Results of studies on cross-pollination in small field environments with regard to donor/receptor surface ratios and flower synchrony are scarce. In 2003 and 2004, six field experiments on cross-pollination were carried out in the cantons of Zug and Zurich, two hilly regions of Switzerland. Three (Monopol, Romario and PR39G12) color-dominant yellow-grain maize varieties (Zea mays L.) were planted in close proximity (0.8 m) to color-recessive white-grain maize (DSP17007). The factors of influence were size of the donor and receptor parts of the field and flower synchrony, tested in a tight grid pattern (2.4 m × 10 m; 6000 ears ha−1). Widely varying field size ratios of donors to receptors (about 4:1–1:8) did not influence the cross-pollination rate at distances of 0–20 m from the pollen donor. The synchrony between pollen shedding of the donor and silking of the receptor had a large impact on cross-pollination. In relation to the mid-phase of silk emergence in the receptor field, a temporal isolation of five and seven days resulted in a significant decrease in cross-pollination by more than 80% in comparison to full synchrony. However, in a receptor field with irregular emergence of a number of weak, late-flowering plants led to a remarkable increase in cross-pollination, despite an average temporal separation of 7 days. Marked cross-pollination was restricted to distances up to 15 m; thus, average rates of cross-pollination above 0.9% were easily managed in small fields.  相似文献   

16.
Triploid tulips have agronomically desirable traits such as vigorous growth and large flower size, but only a portion of all cultivated tulips is triploid. To apply 2n pollen to polyploid breeding of tulips, the polyploidizing agent, nitrous oxide gas (N2O), was applied to bulbs. In tulips, meiosis in anthers occurs inside the bulbs from mid- to late-October. When meiosis in anthers (excised from bulbs) reached metaphase I, we treated other bulbs of the same clones with N2O for 24–48 h. Most of the treated plants produced pollen grains with a wide-ranging or bimodal size distribution, indicating a mixture of n, 2n and aneuploid pollen grains. The use of pollen containing a relatively high proportion of giant pollen grains tended to yield larger numbers of triploids in the progeny. The number of giant pollen grains could be increased when N2O-treated pollen grains were suspended in 10% sucrose and then sieved through a nylon mesh. Very few polyploids were observed in some cross combinations, even those involving pollen with a relatively high proportion of giant grains. Even so, this low polyploid yield most likely is due to a triploid block, because the capsules obtained in the crosses of the diploid×N2O-treated plants contained some abnormal seeds, which were mostly triploid. Embryo culture was useful in rescuing abnormal embryos. The present study reveals that 2n pollen can be produced at high frequency using N2O during tulip breeding.  相似文献   

17.
Summary Two self-incompatible Upper Amazon cacao clones, T85/799 and T79/501, were pollinated with compatible Amelonado pollen subjected to varying doses of gamma irradiation (10–100 Gy). The proportion of flat non-viable beans to fully formed, viable beans in the pods increased with an increase in dosage of gamma rays. At 60 Gy all the beans produced were flat and non-viable, beyond this dosage fruit set was zero. Pollinating the self-incompatible cacao clones with a 1 : 1 mixture of compatible mentor pollen irradiated at 60 Gy and normal self pollen produced a mixture of flat, non-viable beans and fully-formed viable beans. Similar experiments using irradiated pollen with a marker gene suggested that the fully-formed viable beans resulted from selfing. Increasing the proportion of the radiation-treated compatible pollen in the mixture increased the number of fully-formed beans. However, when compatible pollen which had been treated either at 80 Gy or with temperatures of 35° C, 40° C and 45° C for periods of five, ten and fifteen minutes in factorial combination were mixed with self pollen, no successful pollinations were achieved. Pollen viability tests indicated that, whilst pollen treated at 60 Gy were about 50% viable, those treated at either 80 Gy or with temperatures of 35–45° C were mostly not viable. This suggests that, to overcome the incompatibility in cacao, the tubes of the mentor pollen grains used should at least grow into the style. The possible causes for overcoming the self-incompatibility in cacao are discussed.  相似文献   

18.
The grain legume grass pea (Lathyrus sativus L.) is adapted to drought‐prone environments, but the extent and mechanisms of its tolerance are not well understood. In a pot experiment, water deficit was imposed on plants by withholding water from first flowering until predawn leaf water potential (LWPpd) was ?3.12 MPa. Water deficit reduced dry matter, seed yield, harvest index and water use efficiency by 60 %, 87 %, 67 % and 75 %, respectively, when compared with the controls. Flower production stopped when LWPpd fell to ?1.8 MPa. At LWPpd?1.5 MPa, only 25 % of flowers resulted in filled pods (compared with 95 % filled pods in the control) with the rest aborted as flowers (48 %) or pods (27 %). Filled pods had more aborted ovules than controls, resulting in 29 % less seeds per pod. Water deficit reduced pollen viability, germination and the number of pollen tubes reaching the ovary by 13 %, 25 % and 31 %, respectively. Emergence from seeds produced from water‐deficient plants was 21 % less than controls, but seedling shoot dry mass was 18 % higher, in accordance with the 19 % higher seed mass. The sensitivity of flowering to drought limited pod numbers but enabled plants to retain existing pods and develop near‐normal seeds with low β‐N‐oxalyl‐l ‐α‐β‐diaminopropionic acid toxin concentrations. This trait is useful for farming systems reliant on harvested seed for the next crop and in cases where seed size influences the value of the product.  相似文献   

19.
Summary Barriers to interspecific hybridization in Trifolium were investigated by manipulation of mentor pollen treatments, ploidy levels, and compatibility and male sterility systems. Crosses involving the addition of mentor pollen produced fewer seeds and hybrids than crosses involving normal pollination. Lower seed set with mentor pollen was deduced to result from the use of less viable pollen, approximately half the pollen having been killed by alcohol. Pollinations at the diploid level resulted in more hybrids than at the tetraploid level, perhaps because genes for male sterility produced higher female sterility in the tetraploids. The self-compatible stock produced more seeds, mostly selfs, than the self-incompatible stock, but produced more hybrids only in one cross, T. pratense L. × T. diffusum Ehrh. The use of male-sterile female parents reduced selfing but produced fewer hybrids than male-fertile female parents. Techniques of this study were designed to affect prefertilization barriers, but the lack of effect may indicate that postfertilization barriers in Trifolium are of greater importance.Journal Article No. 98-3-208 of Kentucky Agricultural Experiment Station. Published with approval of the Director.  相似文献   

20.
Summary In two highly self incompatible inbred lines of Brussels sprouts the effect of increased atmospheric humidity post pollination was examined immediately following 1) hand pollination of green buds and open flowers, and 2) blowfly pollination of open flowers. Data were obtained for mean number of seeds set per pollination, mean number of fruits setting seed, and mean number of seeds produced per fruit which set for both varieties. Measured as number of seeds produced per minute spent pollinating, it was clear that open flower pollination followed by high humidity conditions was a much more efficient method of producing inbred line seed (46 seeds/minute) than green bud pollination (27 seeds/minute).  相似文献   

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