梨不同品种花粉生活力测定及授粉特性研究

以19个梨品种为试材,用离体培养法测定在不同贮藏温度下花粉生活力,并调查6个杂交组合和15个梨品种自交的结实特性。结果表明,在培养基中加入硼酸和赤霉素可提高花粉生活力;通过镜检发现大慈梨、八月红、黄金梨3个品种花粉败育;在不同的贮藏条件下,温度越低花粉发芽率下降越缓慢,因此在低温条件下适合花粉长久贮藏;在贮藏过程中,均存在\"短期被迫休眠现象\",且随温度的降低被迫休眠恢复时间向后延伸。6个杂交组合的花朵坐果率和花序坐果率平均值为82.54%和94.82%,与自然授粉没有明显差异,因此金二十世纪可以作为鸭梨、雪花梨的授粉树,雪花梨、鸭梨、红安久、红茄梨可以作为黄金梨的授粉树;15个梨品种自交结实率较低,而大慈梨、八月红、黄金梨、秦丰、秀玉、新星、雪花梨、丰水8个品种不结实,在生产上均需配置授粉树才能达到产量需求。     

Agro-morphological traits assessment of Tunisian male date palms (Phœnix dactylifera L.) for preservation and sustainable utilization of local germplasm

Date palm (Ph?nix dactylifera L.) like other crop species in the arid Mediterranean region is being threatened by genetic erosion and climate change. Therefore, the understanding and assessment of the diversity extent of this species is a primary requisite for preserving these crop resources. This study was designed to quantify the potential of Tunisian male date palms using a set of agro-morphological characteristics i.e. flowering traits, inflorescence morphology and pollen quality. The flowering time traits exhibited a trend of precocious phenotype at emergence spathe trait and the dominance of the full-season phenotype at the opening date. At inflorescence morphology, all observed traits expressed wide ranges which reflected the broad variability of the evaluated male genotypes. Significant difference was recorded for the majority of the examined traits with a high significant variation in the tree quantitative traits: Spathe Total Length, Spathe Maximum Width and Length to the brunched part. Pollen viability ranged from 51.10% to 98.75% while the germination rate was between 0.90% and 70.50%. Our phenotypic investigation has allowed the identification of males with desirable agronomic traits which have been genotyped using 18 nuclear SSR markers and a chloroplast minisatellite for preservation and effective utilization purposes.     

Population size,pollinator visitation and fruit production in the deceptive orchid Calypso bulbosa

It has been proposed that in non-rewarding animal-pollinated plants the pollination intensity should decrease with increasing population size and should increase with increasing local abundance of reward-producing plants. To test these hypotheses, we examined how population size, local abundance of Salix caprea, and tree cover were related to pollen removal and fruit production in 16 populations of the deceptive, early-flowering and bumblebee-pollinated orchid Calypso bulbosa in northern Sweden in 3 consecutive years. To determine whether fruit production was limited by pollinator visitation, supplemental hand-pollinations were performed in three populations in 3 years. Finally, to examine whether increased fruit production was associated with a reduction in future flower production, vegetative growth or survival, supplemental hand-pollination was repeated for 5 years in one population. The levels of pollen export, pollen deposition, and fruit set of C. bulbosa varied considerably among years and among populations. The proportion of plants exporting pollen was negatively related to population size, and positively related to density of S. caprea and to tree cover in 1 of the 3 years. In the other 2 years, no significant relationship was detected between proportion of plants exporting pollen and the latter three variables. In no year was there a significant relationship between fruit set and population size, density of S. caprea and tree cover. There was substantial among-year variation in the extent to which fruit production was limited by insufficient pollen deposition and in the amount of weather-induced damage to flowers and developing fruits. Fruit set was consistently higher in hand-pollinated than in open-pollinated plants, but this difference was statistically significant in only one of 3 years. Supplemental hand-pollination in 5 consecutive years increased cumulative fruit production 1.8 times, but did not affect flower production, plant size, or survival. Tree cover was negatively correlated with the incidence of frost damage in 1 year. The results indicate that life-time seed production may be pollen limited in C. bulbosa, and that variation in population size and local abundance of the early-flowering, nectar-producing S. caprea can only partly explain the extensive variation in pollinator visitation among populations of this species.     

Effects of pollen quality and quantity on pollen limitation in Crataegus monogyna (Rosaceae) in NW Spain

Pollen limitation occurs when plants produce less fruits and/or seeds than they would with adequate pollen receipt. If the addition of cross-pollen to stigmas increases fruit/seed production, it is interpreted as an evidence of pollen limitation. Much of the limitation may be associated with the quality rather than quantity of pollen; however, most studies do not discriminate between the two, which may lead to misinterpretation of the results. We studied the effects of quality and quantity of pollen on the reproduction of a northern Spanish population of Crataegus monogyna. The treatments included self- and cross-pollination, and supplementation to open and bagged flowers. The response variables considered were number of pollen grains per stigma, pollen tubes per style, and initial and final fruit set. In the Cantabrian range, C. monogyna requires insect pollinators to set fruit and is partially self-incompatible. We found that the number of pollen tubes did not differ between cross- and self-pollination treatments; however, self-pollinated flowers set less fruits than flowers that received pure cross-pollen or were supplemented with both cross- and self-pollen. The experimental design allowed us to infer qualitative rather than quantitative pollen limitation. Comparison of the number of pollen grains and tubes, and initial and final fruit set among pollination treatments suggested post-zygotic embryo selection against selfed progeny.     

Valorization of date palm (Phoenix dactylifera) fruit processing by-products and wastes using bioprocess technology – Review

The date palm Phoenix dactylifera has played an important role in the day-to-day life of the people for the last 7000 years. Today worldwide production, utilization and industrialization of dates are continuously increasing since date fruits have earned great importance in human nutrition owing to their rich content of essential nutrients. Tons of date palm fruit wastes are discarded daily by the date processing industries leading to environmental problems. Wastes such as date pits represent an average of 10% of the date fruits. Thus, there is an urgent need to find suitable applications for this waste. In spite of several studies on date palm cultivation, their utilization and scope for utilizing date fruit in therapeutic applications, very few reviews are available and they are limited to the chemistry and pharmacology of the date fruits and phytochemical composition, nutritional significance and potential health benefits of date fruit consumption. In this context, in the present review the prospects of valorization of these date fruit processing by-products and wastes’ employing fermentation and enzyme processing technologies towards total utilization of this valuable commodity for the production of biofuels, biopolymers, biosurfactants, organic acids, antibiotics, industrial enzymes and other possible industrial chemicals are discussed.     

新疆产药用植物黑果枸杞有性生殖产出差异的繁殖生态学研究

由于黑果枸杞（Lycium ruthenicum）果实具有重要的保健价值,近年来倍受关注,但其野生资源正遭受着前所未有的采伐压力。目前关于影响黑果枸杞果实产量的有性生殖过程研究较少,本实验对新疆库尔勒地区6个不同生境的野生黑果枸杞居群开展了繁殖生态学观察,并对各居群的访花频率、访花昆虫种类、柱头花粉落置、胚珠数、座果率、结实率和单株果实产量等指标进行了比较分析。结果表明,访花频率与结实率、座果率具有显著正相关关系,说明传粉者是限制黑果枸杞有性生殖的关键因素之一;传粉者种类越丰富的居群其有性生殖产出越高,揭示了传粉昆虫的多样性和丰富度是影响黑果枸杞繁殖成功的重要限制因子。此外,和静县华侨农场和焉耆县霍拉山河沟的黑果枸杞居群生殖产出明显与其传粉成功率相偏离,进一步分析表明,风沙侵蚀和人为采伐对植株的破坏是影响这两个居群果实产量的重要原因。本研究结果对于野生黑果枸杞居群的保护及其人工规模栽培提供了重要的参考依据。     

Quantitatively determined self-incompatibility. IV. Pollination and seed set in Borago officinalis

Summary The outcomes of sequential double pollination, mixed double pollination and single pollination are compared. Single pollination leads to lower seed set than double pollination. Systematic differences between female genotypes are shown to be possible. It is also shown that failure to set seed is generally due to pre-zygotic maternal factors.     

Comparison of two cacao (Theobroma cacao L.) clones for the effect of pollination intensity on fruit set and seed content

We compared the influence of pollination intensity (PI) on fruit set and seed number per pod in two cacao (Theobroma cacao L.) clones, IFC5 (Forastero Lower-Amazon Amelonado), which is self-compatible and known to produce a high number of seeds per pod under open pollination, and SCA6 (Forastero Upper-Amazon), which is self-incompatible and known to produce a low number of seeds per pod under open pollination. With both clones, PI had a positive effect on fruit set, with the maximum rate requiring more than 150 pollen grains per pod. One-half of the maximum rate of fruit set was reached with 39 pollen grains per pod for SCA6, and 78 for IFC5. With SCA6, a significant positive effect of PI on seed number per pod was also observed, with maximum seed number requiring more than 200 pollen grains per pod. In contrast, seed numbers with IFC5 were approximately equal over the PI range 100–800 pollen grains per pod. Patterns of seed number per pod were compared after: (1) open insect pollination, (2) low-intensity hand pollination and (3) high-intensity hand pollination. The patterns obtained with IFC5 under open pollination showed a peak of 40–50 seeds per pod, whereas the distribution patterns were more even with SCA6. The pattern of seed number under open pollination was similar to that obtained with high-intensity hand pollination for IFC5, and with low-intensity hand pollination for SCA6. We concluded that the high number of seeds per pod observed with IFC5 under natural insect pollination may be explained by a high number of compatible self-pollen grains on the stigma and by a severe drop of low-pollinated flowers eliminating potential lowfilled fruits. With SCA6, however, the number of compatible pollen grains deposited on the stigma was probably low under open pollination, and the flowers required lower pollen quantities to set fruit, which resulted in a high frequency of low seed numbers per fruit. This difference in the capacity to set low-seeded fruits might be considered as an adaptive trait related to the mode of reproduction.     

Pollination thoroughness and maternal yield regulation in wild radish,Raphanus raphanistrum (Brassicaceae)

Summary Under conditions where resources are limited, there are often negative correlations between components of maternal yield, or between fruit and flower production. Pollination, in turn, may vary among individuals and influence total maternal expenditure. We examined the impact of variation in pollination thoroughness upon yield components and overall plant growth in wild radish (R. raphanistrum) plants grown in the greenhouse. Plants received different pollination treatments in which 0% to 100% of all flowers produced were hand-pollinated. Fruit set was increased by hand-pollination, but rarely exceeded 30%, even when more than 50% of the flowers were pollinated. Plants receiving more thorough pollination or having greater proportion fruit set produced significantly smaller seeds. Seed number per fruit was not influenced by pollination treatment. Mean values of yield components and interactions between components often varied among plants from different maternal families. Increasing pollination thoroughness also resulted in dramatic decreases in flower production. If male fitness is related to flower number, there may be a tradeoff between maternal fecundity and successful pollen export operating at the whole-plant level in this species.     

Unpaved roads disrupt the effect of herbivores and pollinators on the reproduction of a dominant shrub

Anthropogenic linear developments, such as trails and firebreaks, also called soft linear developments (SLD), can influence animal behavior, altering the ecological interactions in which animals are involved. For example, SLD can affect the behavior of pollinators and herbivores, but little is known about the combined effect of these three elements on plant reproduction.We evaluated the combined effect of SLD, insect pollinators and herbivores (ungulates) on three reproductive output variables (fruit set, seed set, and seed mass) of a Mediterranean shrub (Halimium halimifolium). We considered two different habitats (SLD verges vs. adjacent scrublands), two scenarios of herbivory (with and without ungulates), and three scenarios of pollinator activity (without pollinators, with manual pollination and with natural pollination).SLD had contrasting effects on H. halimifolium reproduction. In the absence of herbivores, overall fruit set was lower in the verges of SLD than in adjacent scrublands, probably due to lower flower pollination rates. Where herbivores were present, overall fruit set was similar between habitats, because ungulate browsing was lower in SLD verges than in adjacent scrublands. The quantity and weight of seeds per fruit was similar in both habitats, probably because all fertilized flowers received similar amounts of pollen.SLD can alter the interaction among pollinators, herbivores and plants, leading to changes in the reproductive performance of the latter. These changes can have strong negative impacts on endangered plants that rely on fruit and seed production to persist. However, SLD verges could be safe places for plants particularly sensitive to herbivory by ungulates.     

Habitat dependent pollination success in a Cape orchid

Summary We examined the pollination success of Disa uniflora (Orchidaceae) in two habitats. Plants occurring in a rocky gorge were far more successful than plants occurring in an adjacent open valley. More than 55% of flowers in the gorge were pollinated and set fruit compared with less than 25% of flowers in the valley. These differences are explained by the preference of Meneris tulbaghia (Satyridae), the exclusive pollinator of the orchid, for rocky, sheltered habitats. Fruit set of hand-pollinated flowers did not differ significantly between the two habitats, indicating that resources did not account for the variation in fruiting success.     

Flowering Phenology, Pollination, and Fruit Set of Cypripedium macranthos var. rebunense, a Threatened Lady's Slipper (Orchidaceae)

Cypripedium macranthos var. rebunense, was preliminarily studied on Rebun Island, Hokkaido, Japan, for conservation of this threatened orchid. The functional longevity of individual flowers varied from 0 to 18 days, a determining factor being the wind conditions at the growing sites. The flower was self-compatible but needed a pollen vector for fruit production. It lacked nectar and adopted a deceptive pollination system. Queens of a bumblebee, Bombus pseudo-baicalensis, were found to be pollinators but their visits were infrequent. Fruit set was 8.3% at one study site but only 1.2% at another, probably due to interference from the many visitors who came to see the flowers. Based on the results, conservation and management of lady's slipper were discussed. The need for less human interference and for preservation of the interactions between lady's slipper and its pollinator or other plant species with floral rewards is stressed. Received 1 November 2000/ Accepted in revised form 15 March 2001     

Characterization of ten date palm (Phoenix dactylifera L.) cultivars from Saudi Arabia using AFLP and ISSR markers

Date palm is the most economically important plant in the Middle East due to its nutritionally valuable fruit. The development of accurate DNA fingerprints to characterize cultivars and the detection of genetic diversity are of great value for breeding programs. The present study explores the usefulness of ISSR and AFLP molecular markers to detect relationships among 10 date palm (Phoenix dactylifera L.) cultivars from Saudi Arabia. Thirteen ISSR primers and six AFLP primer combinations were examined. The level of polymorphism among cultivars for ISSRs ranged from 20% to 100% with an average of 85%. Polymorphism levels for AFLPs ranged from 63% to 84% with an average of 76%. The total number of cultivar-specific markers was 241, 208 of which were generated from AFLP analysis. AJWA cultivar had the highest number of cultivar-specific ISSR markers, whereas DEK, PER, SUK-Q, SHA and MOS-H cultivars had the lowest. RAB and SHA cultivars had the most and least AFLP cultivar-specific markers, respectively. The highest pairwise similarity indices for ISSRs, AFLPs and combined markers were 84% between DEK (female) and PER (female), 81% between SUK-Q (male) and RAB (male), and 80% between SUK-Q (male) and RAB (male), respectively. The lowest similarity indices were 65% between TAB (female) and SUK-Q (male), 67% between SUK-A (female) and SUK-Q (male), and 67% between SUK-A (female) and SUK-Q (male). Cultivars of the same sex had higher pairwise similarities than those between cultivars of different sex. The Neighbor-Joining (NJ) tree generated from the ISSR dataset was not well resolved and bootstrap support for resolved nodes in the tree was low. AFLP and combined data generated completely resolved trees with high levels of bootstrap support. In conclusion, AFLP and ISSR approaches enabled discrimination among 10 date palm cultivars of from Saudi Arabia, which will provide valuable information for future improvement of this important crop.     

Determination of heavy metals in the fruit of date palm growing at different locations of Riyadh

Exposure of heavy metals to human beings has risen dramatically in the last 50 years. In today’s urban and industrial society, there is no escaping from exposure to toxic chemicals and heavy metals. Humans are more likely to be exposed to heavy metal contamination from the dust that adheres to edible plants than from bioaccumulation. This is because it is very difficult to wash off all the dust particles from the plant material before ingesting them. The objectives of this experiment were to determine the concentrations of lead (Pb) and cadmium (Cd) in washing residues and in the tissues of fruits of date palm growing in 14 sites of Riyadh and also to assess whether the fruits were safe for human consumption. The washing residues and tissue of date palm fruits collected from different sites showed the presence of significant amounts of the Pb and Cd. The concentration of Pb in the dust and fruit tissue increased with increasing anthropogenic sources. Therefore, fruits of date palm might be used as a pollution indicator; it might be recommend that fruits of date palm could be safe for human consumption after washing. The mean concentration of Pb and Cd in all the samples collected from different sites is within the safe limits recommended by FAO/WHO.     

Effects of pollination intensity on Lesquerella fendleri seed set: variation among plants

 The amount of pollen arriving on a flower can be an important determinant of seed production. I investigated the effect of varying pollen loads on seed set of the perennial desert mustard Lesquerella fendleri. To do this, I quantified the dose response relationship between stigmatic pollen load and seed set per fruit using over 400 flowers from 13 greenhouse-grown plants. Seed set per fruit generally increased with pollen up to about 100 pollen grains, then reached a plateau. A negative exponential regression of seed set on pollen load for the pooled data explained less than 10% of the observed variation in seeds per fruit. However, accounting for variation among individual plants in the dose-response relationship increased explained variation to 40%, indicating that plants responded differently to the same amount of available pollen. Plants varied little in the initial slope of the dose-response curve, but differed substantially in the asymptote, which ranged from 3 to 16 seeds. This limit is not imposed by ovule number, and may instead result from variation among plants in vigor, propensity to abort seeds, or in gender specialization. Such variation among plants in dose-response relationships has important consequences for understanding pollination limitation and pollen competition. Received: 29 January 1996 / Accepted: 6 August 1996     

Secondary pollen carryover by ants in a natural population of Scleranthus perennis (Caryophyllaceae)

Summary Secondary pollen carryover is defined as the process whereby a pollinator receives previously deposited pollen grains when visiting a flower and transfers them into a new (secondary) carryover sequence. The secondary pollen carryover in a system of ants, Formica rufibarbis, visiting Scleranthus perennis (Caryophyllaceae) was studied using fluorescent dyes as pollen analogues. The mean secondary carryover was found to be 1.2 flowers compared with 4.5 flowers for the primary carryover. The number of dye grains deposited per flower visited is lower and the frequency of zero deposition is higher in the secondary carryover sequence than in the primary.     

Influence of the pH of the stigmatic exudate on male-female interaction in Rosa hybrida L

Summary The in vitro germination of rose pollen is influenced by the pH of the medium. Both germination percentage and length of emitted pollen tubes were maximal for in vitro germination and tube elongation at pH 5 and minimal at pH 3 and 9 (Rosa hybrida L. var P 30 pollen). Three varieties characterized by having a stigmatic exudate of pH = 5 and another three varieties having one of pH = 9 were pollinated with the same pollen. Pollination effectiveness, as indicated by hip set (number of hips/pollmated flowers × 100) and mean number of achenes per hip, were significantly different: it was much higher for the varieties with the stigmatic exudate of pH = 5. pH control on pollination efficiency and subsequent fecundation success is proposed and discussed.     

Physical site characteristics limit pollination and fruit set in the dioecious hydrophilous species,Vallisneria americana

Experimental and observational studies of the submersed, freshwater macrophyte Vallisneria americana Michx. revealed that depth, wind and wave exposure, and current velocity may all influence fruit set. In this dioecious species, long-pedunculate female flowers are pollinated by free-floating male flowers at the water surface. Average fruit set in the natural populations studied varied from zero to 97% of the flowers observed. With increasing water depth in New York and Pennsylvania lakes, female plants continued to flower, though these flowers were unable to reach the surface, and consequently, did not set fruit. Fruit set was also lower in relatively open sites exposed to wind and waves, presumably because male flowers do not remain in the vicinity of female flowers long enough for effective pollination. This was particularly striking at a site with low male flower densities, but fruit set was increased to 100% at that site by confining the floating male flowers within a field enclosure. In a river, fruit set was negatively correlated with surface current velocity, and was reduced to zero in current velocities greater than 0.30 m · s^–1. Fruit set in V. americana appears to be restricted or precluded by physical environmental conditions in a variety of sites.     

A new technique for monitoring pollen flow in orchids

Summary The orchid Prasophyllum fimbria is pollinated by nectar-feeding native bees and wasps. The pollinia are patially separated from the viscidium by a stipe so that pollinia can be labelled with coloured histochemical stains without interfering with pollinarium removal. Pollen flow was monitored by following the movement of the coloured pollen in several populations of P. fimbria in Western Australia. Statistical analysis confirmed that pollen labelling did not interfere with pollinarium removal or subsequent pollination of the labelled flower. Fifty eight labelled pollinaria were removed by vectors from 16 test spikes, with a total of 125 flowers on 47 spikes receiving labelled pollen. An average of 2 flowers received pollen for every pollinium removed but up to 6 flowers received pollen from a single collinium. No significant differences between mean vector flights and pollen flow distances were detected. On average, geitonogamous transfers only accounted for 22% of all pollinations. This is a simple and inexpensive technique for the direct labelling of pollen with minimal disruption to the pollination system and may have applications in other plant families.