首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 62 毫秒
1.
Summary

Supplementary pollination of almond using electrostatic techniques was tested in a three year study (1996–1998) in Northern Israel. We used an electrostatic pollination device and tested its effects on fruitlet set, fruit set, yield weight and nut weight. We also tested its ability to pollinate flowers on the tree from the distal to the proximal part of the branches. We found that when individual branches were pollinated, fruitlet set was in accordance with the expected deposition rate of pollen grains on the stigma: electrostatic 1 open pollination > non-electrostatic + open pollination + open pollination > electrostatic pollination > non-electrostatic pollination > spontaneous self pollination. Fruit set results showed the same pattern but were not as precise. Electrostatic pollination of individual trees resulted in an insignificant increase in pollen germinability on the stigma. The highest germinability was on the distal part of the branch and the lowest was on the proximal part of the branch, in all pollination treatments. Electrostatic pollination increased yield as compared with non-electrostatic and open pollination. Nut weight, however, decreased slightly with increased yield. We suggest that electrostatic pollination can be an important method for pollen supplementation in almond orchards when honeybee pollination is insuf®cient and when the trees can withstand the added portion of nuts, resulting from improved pollination.  相似文献   

2.
An improved in vitro pollen germination method was developed for avocado (Persea americana Mill.). The effect of different concentrations of sucrose, polyethylene glycol (PEG), Mg and Ca on pollen germination was evaluated in order to determine the optimal pollen germination medium, i.e. that maximizing the percentage of pollen germination and minimizing the percentage of bursted pollen grains. Once the germination medium was optimized we used it to study the effect of temperature on in vitro pollen germination and tube growth in different cultivars from the three botanical varieties of avocado, that differ in their adaptation to environmental conditions. Significant differences in percentage of pollen germination and in pollen tube growth were observed among cultivars. These results could have implications not only for optimizing pollen management in avocado but also to select the best pollinizers for a particular cultivar.  相似文献   

3.
Summary

The timing of fungicide and antibiotic applications in fruit crops often overlaps flowering and pollination. Numerous studies report detrimental effects of chemical applications on pollination, fruit set and yield. However, field results can be quite variable even when similar compounds are tested on the same crop. Problematic is that field variables unrelated to the effects of pesticides on reproductive activities can mask results. In the current study, we specifically investigated the effects of selected pesticide sprays applied to stigmas, on subsequent pollen germination and tube growth. Using two model systems, apple and almond, sprays were applied to detached emasculated flowers under constant laboratory conditions using an electronically controlled robotic apparatus which simulated a field sprayer. flowers were pollinated at specific times after spraying, and pollen tube numbers and growth assessed using fluorescence microscopy. The pesticides evaluated were for apple: captan, myclobutanil and streptomycin; and for almond: azoxystrobin, myclobutanil, iprodione and cyprodinil. In apple, captan significantly reduced pollen germination, by 20% compared with water controls when pollination was conducted 18 h after treatment. The number of tubes that reached the basal part of the style within 20 h was not affected. In contrast, myclobutanil and streptomycin had no significant effect on pollen tube growth. With almond, none of the sprays significantly affected pollen germination or tube growth.  相似文献   

4.
Summary

Eight apricot (Prunus armeniaca L.) cultivars and selections were self- and cross-pollinated in order to determine their pollen and stylar compatibility. Overall, 40 pollination combinations were examined. Pollen-tube growth in pistils pollinated in the laboratory was analysed using fluorescence microscopy. Three inter-incompatiblity groups of cultivars were found, of which two had not been described previously, while an existing group was expanded with one additional cultivar. The first group consisted of three Hungarian cultivars (‘Ligeti Orias’, ‘Cegledi Orias’, and ‘Szegedi Mammut’) and a Moldavian cultivar (‘Kostjuzhenskyi’). The second group consisted of two American cultivars (‘Stark Early Orange’ and ‘Nugget’). The third group consisted of two Serbian selections (‘Novi Sad Early’ and ‘Frushka Gora Early’). In the incompatible cultivar combinations, pollen-tube growth stopped in the style with the formation of the characteristic swelling. In the compatible combinations, the pollen tubes reached the ovary in the majority of the pistils examined.  相似文献   

5.
Pod-setting in runner bean crops depends on the building up and maintenance of a sufficiently large population of efficient insect pollinators, and this appears to be affected by the early spring weather.

Runner bean flowers were visited and could be pollinated both by bumblebees (Bombus spp.) and honeybees (Apis mellifera). Visits to the front of the flower for nectar or pollen resulted in pollination, but “nectar-robbing” via a hole bitten through the underside of the flower, caused little or no pollination. During periods of intense nectar-robbing activity, pollination efficiency varied widely and depended largely upon whether or not insects were also collecting pollen from the crop.

A technique was devised for measuring the daily insect pollinating efficiency in a crop, that is, the actual daily pod-set as a percentage of the potential daily pod- set. A simple visual method for assessing the current day’s pollinating activity in the field is described, and the efficiency thus indicated compares well with results obtained from experimental pollination efficiency measurements.  相似文献   

6.
Female pistachio (Pistacia vera) trees were hand pollinated with pollen from three different male genotypes 0,1,2,3 and 4 d after anthesis. Results were measured by mature fruit set and by fluorescence microscopy of pollen germination and tube growth in the pistil. Maximum pollen tube growth and fruit set of split nuts was achieved following pollination within two days of anthesis. Three day old pistils supported pollen tube growth, but fruit set was low. Four day old pistils supported little pollen tube growth or fruit set. Significant differences were also apparent between pollen parents, with low pollen tube growth and fruit set following interspecific pollination with P. atlantica pollen. All pollen tubes were observed to penetrate chalazogamously, and parthenocarpic production of blank fruits occurred in both unpollinated and pollinated treatments. The results indicate that for optimum fruit production of pistachio, pollen transfer must be achieved within 2 d of anthesis and pollination by P. atlantica should be avoided.  相似文献   

7.
ABSTRACT

Two artificial pollination field trials were carried out in Central Chile (32°S. Lat.) during the 1999-2000 season with ‘Hay-ward’ kiwifruit plants (Actinidia deliciosa (Chev.) Liang et Ferguson). The treatments for both trials used pollen collected from ‘Matua’ and included: flower to flower hand pollination; hand pollination using a velvet pad attached to a handle; and mechanical pollination using a portable pollen (1:1, pollen: licopodium) dusting machine; and a control treatment without artificial pollination. Trial 1 did not include bee hives as did Trial 2. In Trial 2, half of the selected shoots in each plant were isolated from bee pollination by means of a light fabric bag. A block design with 5 replications of one plant each was used in Trial 1, while in Trial 2 a fully random split plot (with and without isolation) with 5 replications was used. In both trials, flower to flower and pad pollination increased fruit set, fruit size, seeds and fertilized locules per fruit. Mechanical pollination also increased these variables but to a lesser degree. In the split plot design carried out in the Trial 2, even though there was an interaction between isolation and pollination treatment, the supplementary bee pollination tended to increase fruit size, seeds and fertilized locules per fruit.  相似文献   

8.
Summary

Male wild bees visit flowers to feed and, despite their lack of specialised organs for carrying pollen, simultaneously pollinate them. We analysed the pollinating efficiency of the males of two bee species for blackcurrant (Ribes nigrum L.): red mason bee (Osmia rufa L.) and bufftailed bumblebee (Bombus terrestris terrestris L.). Both bee species are commercial pollinators and many males are produced during their rearing. Gauze sleeves were used to isolate the inflorescences and to keep the males inside (one per sleeve). In each experimental group, there were six shoots with four neighbouring inflorescences (n = 24). The sleeves were also used to prevent other bees from reaching the flowers, and to allow self-pollination. Non-isolated flowers were pollinated by free-range bees. The effect of male bee pollination was similar to that of free-range bee pollination. The percentages of flowers that developed into fruit were as follows: male bufftailed bumblebee pollination, 79.5%; free-range bee pollination, 71.1%; male red mason bee pollination, 65.1%; and self-pollination, 46.4%; while the mean numbers of fruit per raceme were 5.0, 4.4, 3.6, and 2.4, respectively. The number of non-pollinated flowers per raceme (ranging from 1.3 – 2.8) exhibited an inverse relationship to these numbers of fruit. Our observations showed that male wild bees can pollinate blackcurrant flowers successfully, and could potentially be useful in other crops.  相似文献   

9.
Summary

Hamelia patens Jacq., commonly called firebush, is a fast-growing, semi-woody, evergreen, perennial shrub in the family Rubiaceae. It is native to central southern Florida, USA and is cultivated on a wider scale as an ornamental plant in home gardens of India. From previous analyses, it was found that sexual reproduction in H. patens was limited due to self-incompatibility and was overcome by intraspecific pollination between morphologically different accessions. Diffusion plate assays, spectrophotometric analysis, and in vitro bioassays were conducted to measure RNase activity among stigma proteins. After compatible cross-pollination, the RNase activity was less than during incompatible pollination. RNase activity was present in extracts as well as leachates of the stigma. Diffusion plate assays and spectrophotometric assays were used to measure the RNase activity. In vitro assays revealed that RNase activity was essential for the inhibition of pollen tube growth. Our study confirmed that RNase-based gametophytic self-incompatibility operates in H. patens.  相似文献   

10.
SUMMARY

Pollinator performance was evaluated in kiwifruit to select pollinators for cv. Hayward adapted to the cultural conditions of southern Europe. Flowering time was determined in forty male seedlings. From, these, nine were selected for having a flowering period overlapping with ‘Hayward’. In these nine males, as well as in the commercial pollinators‘Matua’ and Tomuri’, the production of pollen was studied over two years, investigating pollen quantity through flower density and pollen production per flower. Likewise, in vitro pollen viability and its in vitro germination were recorded to study pollen quality. Finally, in vivo pollen performance was studied through fruit set and fruit characteristics in controlled hand pollinations. Two males have been selected with a flowering period coincident with ‘Hayward’, which produce more than twice as much germinable pollen than commercial pollinators. Whilst there were no significant differences in pollen quality or in fruit production, clear differences existed for pollen quantity in terms of both flower density and pollen production per flower. As pollen quantity, together with flowering time, can be easily evaluated at an early stage, this is encouraging for future selection ofkiwifruit pollinators.  相似文献   

11.
The present study aimed to study the flower and pollen structure, pollen viability, in vitro pollen germination of ‘Kagzi Kalan’ lemon (Citrus limon (L.) Osbeck), and in vivo pollen tube growth in self- and cross pollination to understand the mechanism of seedlessness. The results revealed that Kagzi Kalan had tetra-colporate spherical shaped pollen of uniform size. The results of Acetocarmine and FDA test and in vitro germination indicated normal pollen viability and germinability in Kagzi Kalan. In vivo pollen tube growth showed > 50% pollen germination on stigma in all treatments though a greater number of pollen tubes at the mid style, base of the style, and near the ovule was found in cross pollination. Contrary to this, despite optimum pollen germination (53.51–70.37%) in self-pollination treatments, none of the pollen tubes reached the base of the style due to abnormal growth of pollen tubes, viz. curvatures, inhibition of pollen tube growth, and callose deposition. The inhibition of pollen tubes at the mid style under self-pollination treatments, and production of seeded fruits under cross pollination treatments, indicate the presence of self-incompatibility and the site of inhibition of pollen tubes. Thus, gametophytic self-incompatibility (SI) caused seedlessness in Kagzi Kalan by blocking fertilization in the ovary.  相似文献   

12.
Summary

In a previous study, the apple ‘Jonathan’ was shown to be semi-compatible with the ‘Topred’ sport of ‘Red Delicious’, the main cultivar in Israel. This incompatibility led to reduced pollination potency, explaining the low yield obtained from ‘Topred’ rows adjacent to ‘Jonathan’. Hence, the importance of identifying the level of compatibility for all ‘Topred’ pollinators became apparent. By analysing S-allele by PCR with primers for the various S-alleles of the cultivars in the ‘Topred’ orchard, including S10 and S28, which were cloned in this study, it was evident that apart from ‘Jonathan’, the common pollinators for ‘Topred’ are fully compatible with it. The ability to identify all S-alleles in the ‘Topred’ orchard was also utilized to resolve the observation that, although ‘Topred’ is considered self-incompatible, self-pollinated, net-caged, ‘Topred’ flowers set some fruit. Applying PCR-analysis of S-alleles to the progeny of the suspected self-pollinated ‘Topred’ fruit revealed that the fruit-set was the outcome of cross-pollination, perhaps the consequence of fertilization by wind carried pollen. Hence, the notion that ‘Topred’ is totally self-incompatible was confirmed and the efficiency of progeny PCR S-allele analysis for the determination of the pollen donor was exhibited.  相似文献   

13.
ABSTRACT

Our work on strawberry pollination started in 1996 because die top cultivar grown in France is ‘Gariguette’ and growers get good prices widi this cultivar very early in the season (March-April) as the quality of the product is well recognized. Crop management aimed at earliness (early covering, covering with a layer of non-woven fabric or under greenhouse polyethylene film, heating, etc.) induces the plant to flower under conditions unfavorable for pollination such as short days with low irradiation levels and temperatures around 8-10°C which hinder pollen formation. Such conditions often lead later on to problems in strawberry development and shape (large areas with unfertilized ovules, furrows, etc.). This is especially true for primary flowers, which should provide the largest strawberries. A preliminary study was first conducted to assess whether pollination was, indeed, a limiting factor for strawberry production in early crops and whether female reproductive structures also have played a role as well. When this work was completed and pollination was demonstrated as the main limiting factor for strawberry development from the first batch of flowers, the authors studied the different pollen vectors and quantified their action to determine their incidence in terms of production under “limiting” early cropping conditions.  相似文献   

14.
Papaya pollen viability and storage   总被引：2，自引：0，他引：2  
Papaya pollen viability, tube growth and storage were studied. Pollen germination on a drop of modified Brewbaker medium at 22–26°C closely reflected in vivo germination. Two vital stains gave pollen viability estimates that correlated closely with pollen germination percentage. The time from pollination to first ovule penetration was 25 h at 28°C, no in vitro pollen germination was observed at 5°C and at 40°C pollen tube growth was retarded. High relative humidity (70–80%) hastened the process compared with low relative humidity (30–40%).

Pollen could be stored successfully for 6 months when kept at − 18°C in a deep-freezer. Storage of pollen for the winter months, during which no or very little viable pollen is formed in the coastal area of Israel, seems a practical means to ensure adequate fruit set.  相似文献   


15.
Summary

Field and laboratory experiments were conducted to study if rain could wash-off pollen grains from the surface of the stigma and consequently affect the efficiency of fertilisation in loquat (Eriobotrya japonica Lindl.). Flowers of the loquat cultivar, ‘Dawuxing’, growing in the field, were emasculated, pollinated by hand with pollen of the cultivar ‘Longquan No.5’, then sprayed with water to simulate the effect of rain at –8, –4, –2 h before, –0 h (immediately before hand-pollination) , +0 h (immediately after hand-pollination), and 2, 4, 8, or 12 h after pollination. A control to which no water treatment was applied was also included in the assay. Meanwhile, additional assays were performed in the laboratory to improve the resolution of the field study by using earlier treatments. Here, treatments were performed by pollinating, immersing, and shaking a branch with flowers in a container of water in the laboratory –120, –60, –30, –0, +0, 30, 60, or 120 min before or after hand-pollination. One additional sample was immersed, shaken, then hand-pollinated, and immersed and shaken (ISPIS) again. The results showed that the numbers of pollen grains that germinated, and the percentages of fruit set, differed significantly between the –4, –2, –0, or +0 h treatments and the non-water-treated control in the field assays, especially in the case of the –0 h and +0 h treatments in which the stigmas were washed immediately before or after hand-pollination. However, the –8, 2, 4, 8, and 12 h treatments did not show significant differences from the non-treated control. On the other hand, the laboratory experiments showed that all washing treatments reduced the number of germinated pollen grains retained on the stigma, and the immersion treatments at –30, –0, +0, or 30 min as well as the additional ISPIS treatment, showed significant differences from the non-treated controls in the numbers of pollen grains retained on the stigmas. In conclusion, the results showed that adhesion of pollen grains to the stigmas in loquat was rapid and strong, and that the simulated rain treatment was not able to wash-off pollen grains completely from the stigma surface, except in the –0 h and +0 h treatments.  相似文献   

16.
The floral response of the type A avocado cultivars ‘Reed’, ‘Wurtz’, ‘Rincon’ and ‘Jalna’, and the type B cultivars ‘Bacon’, ‘Ryan’, ‘Edranol’, ‘Sharwil’ and ‘Hazzard’ was tested under growth-cabinet conditions of 17° C day, 12° C night, with a 12-h photoperiod and photon flux density of 400 μE m?2 s?1 (400–700 nm). Most of the flowers of all type A cultivars and the type B cultivar ‘Bacon’ had both a female and a male stage. None of the flowers of the other type B cultivars had a female stage but opened in the male stage only. Hand pollination resulted in some ovule penetration in the cultivars with female stage flowers. In those with only male-stage flowers, the pollen tubes grew no further than the style. Maintenance of fertility under low-temperature conditions during flowering appeared to be partly, but not entirely, linked to the type A flowering cycle.  相似文献   

17.
Summary

The current practice of manual emasculation of tomato ¯owers for hybrid seed production is labour-intensive and contributes signi®cantly to the high cost of seed. Here we report on a photoperiod-sensitive, single gene male-sterile mutant (7B-1) in tomato which is 100% male sterile in long days (LD, minimum of 12.h daylength) in summer ®eld conditions, but produces many male-fertile ¯owers in short days (SD, 8.h). In LD, 7B-1 ¯owers contain stamens that are pale, short and in the anthers microspore mother cells are differentiated but meiosis does not occur, i.e. microspores and pollen grains are not formed. Unlike the wild type ¯owers, the style and stigma of 7B-1 ¯owers are well exposed and this allows for ready access for pollination without emasculation. In SD, mutant ¯owers possess normal-looking orange-yellow anthers that enclose the stigma and produce normal viable pollen, which when used for pollination of 7B-1 ¯owers yield good fruit- and seed-set. The 7B-1 seed in turn generate a 100% population of male-sterile plants all of which can be used as female parents for hybrid seed production. The female fertility is not affected in 7B-1 ¯owers in both LD and SD conditions. The 7B-1 mutant has been grown in various ®eld locations including, Saskatoon, California, Florida and in Chile, and at all locations it has shown stable male sterility. The 7B-1 mutant is a simple, natural and costeffective system that has a strong potential for use in commercial-scale production of tomato hybrid seed.  相似文献   

18.
An efficient protocol for in vitro maturation of very immature, <10 mm, avocado embryos has been developed. The efficiency of plant recovery as well as the quality of the resulting plants was greatly improved by including a maturation phase prior to induction of germination. The influence of different factors, such as the gelling agent, organic supplements or abscisic acid, on embryo maturation and subsequent germination was tested. Optimum conditions were met when maturation was carried out in B5m medium supplemented with the Jensen's amino acids, an extra 88 mM sucrose and 6 g l−1 agar as gelling agent. At these conditions, embryos which had been collected 68 days after pollination germinated at a 65% rate in solid medium, giving rise to healthy and vigorous plantlets. Anatomical differentiation and storage product accumulation occurring during the in vitro maturation phase were studied by means of histological techniques. Results obtained revealed that, at the end of the in vitro maturation period, embryos resembled the pattern previously established for avocado embryos matured under in vivo conditions: histodifferentiation had been accomplished and starch granules and protein bodies were abundant.  相似文献   

19.
Summary

We explored the effects of pollination method (hand cross-, hand self-, automatic self-, and open-pollination) and pollen source on fruit set and growth in four red-skinned pitaya (Hylocereus spp.) cultivars [‘Vietnam White’ (‘VNWhite’), ‘Chaozhou 5’, ‘Orejona’, and ‘F11’] in Taiwan.‘VN-White’ has white flesh, while the other three cultivars have red flesh. There were no significant differences in pollen viability or germination rate among the four cultivars, irrespective of whether the pollen was collected at night (approx. 20.30 h) or on the following morning (approx. 08.30 h).The results also indicated that ‘VN White’ was fully self-compatible and exhibited a high fruit set percentage (80 - 96%) following all pollination treatments. This cultivar produced the largest fruit from both hand self- and openpollination, compared to the three other cultivars tested. ‘Chaozhou 5’ was partly self-compatible, and ‘Orejona’ and ‘F11’ were completely self-incompatible. Hand cross-pollination significantly increased the fruit set percentages and mean fruit fresh weights (FWs) in ‘Chaozhou 5’ and ‘Orejona’. Pollen source also significantly affected the fruit set percentage and fruit FW. ‘VN-White’ (after self-pollination) and ‘Chaozou 5’ (after crossing with ‘VN-White’) gave superior fruit set percentages and fruit FWs. Reciprocal crosses between ‘Orejona’ and ‘F11’ also resulted in high fruit set percentages as well as large fruit in both cultivars. Therefore, the source of pollen and the method of pollination can affect fruit production in some cultivars of pitaya. Self-compatibility in ‘VN-White’ concurs with the morphology of its flowers in which the anthers lie in close proximity to the stigma.The distance between the anthers and the stigma may be used an indicator of whether hand pollination is necessary for a pitaya cultivar.  相似文献   

20.
Summary

The recent introduction of new self-incompatible varieties of apricot has required further research on the extent of self-incompatibility in apricot and its genetic determinism. The different laboratory and field techniques utilized to date for incompatibility studies in apricot have often given markedly diverging results, leading to difficulty of interpretation. The purpose of this study was therefore to make a critical assessment of the reliability of the various methods, to obtain a more precise tool for compatibility studies. Forty-eight apricot crosses were assessed over a two-year period and the results compared using the normal field techniques (active pollination without bagging, active pollination with bagging and passive pollination) and laboratory tests (fluorescence test). The present study reports on some aspects of the different techniques and offers methodological suggestions for improved practical application of the various tests.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号