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1.
Kai Sheng  Saichao Wei  Jun Mei  Jing Xie 《Phyton》2021,90(1):291-305
Low-temperature storage is extensively used to optimize the postharvest life of various fresh fruits. However, red pitahaya (Hylocereus polyrhizus) fruits are sensitive to chilling injury (CI), which leads to the limitation of low-temperature storage. In this study, red pitahaya fruits were stored at 2, 4, 6, 8, and 10°C, respectively, for 27 days to determine the appropriate storage temperature. During the storage of red pitahaya fruits, storage at 8°C was more effective in suppressing decay and maintaining quality than other low temperatures. Low-temperature (2, 4, and 6°C) storage decreased weight loss (WL) and maintained higher content of titratable acidity (TA), soluble sugars (SS), and total phenolics (TP) but different degrees of CI were detected. No CI was observed at 8°C and 10°C. Red pitahay as stored at 8 and 10°C were associated with better color evaluation, lower electrolyte leakage (EL), respiration rate, and lipoxygenase (LOX) activity, and higher fruit firmness, superoxide dismutase (SOD) activity, and catalase (CAT) activity. However, higher storage temperature (10°C) resulted in higher metabolic activity leading to lower quality and antioxidant capacities compared with 8°C. Therefore, our results demonstrated that red pitahaya stored at 8°C exhibited a protective effect on fruit quality and resisted CI development during storage.  相似文献   

2.
The reproductive biology, reward production and pollination mechanism of Trichocentrum pumilum were studied in a gallery forest in the interior of the State of São Paulo, southeast Brazil. The floral visitors and pollination mechanism were recorded, and experimental pollinations were carried out in order to determine the breeding system of this species. Trichocentrum pumilum blooms in spring. Each paniculate inflorescence bears an average of 85 flowers that present a central yellow callus and finger‐like trichomes on the lateral lobes of the lip. A lipoidal substance is produced and stored among these trichomes. In the studied population, T. pumilum is exclusively visited and pollinated by two bee species (Tetrapedia diversipes and Lophopedia nigrispinis). Pollinaria are deposited on mouthparts of bees during collection of the lipoidal substance from the lateral lobes of the labellum. Trichocentrum pumilum is self‐incompatible and pollinator‐limited. Natural fruit set was low (9%, compared to 45% in experimentally cross‐pollinated flowers). Potentially viable seed exceed 97% in fruits obtained through cross‐pollination and in natural conditions (open pollination).  相似文献   

3.
This study aimed to determine if self‐pollination is needed to trigger facultative parthenocarpy in self‐incompatible Clementine mandarins (Citrus clementina Hort. ex Tan.). ‘Marisol’ and ‘Clemenules’ mandarins were selected, and self‐pollinated and un‐pollinated flowers from both cultivars were used for comparison. These mandarins are always seedless after self‐pollination and show high and low ability to develop substantial parthenocarpic fruits, respectively. The time‐course for pollen grain germination, tube growth and ovule abortion was analyzed as well as that for carbohydrates, active gibberellins (GA1 and GA4), auxin (IAA) and abscisic acid (ABA) content in the ovary. ‘Clemenules’ showed higher pollen grain germination, but pollen tube development was arrested in the upper style 9 days after pollination in both cultivars. Self‐pollination did not stimulate parthenocarpy, whereas both un‐pollinated and self‐pollinated ovaries set fruit regardless of the cultivar. On the other hand, ‘Marisol’ un‐pollinated flowers showed greater parthenocarpic ovary growth than ‘Clemenules’ un‐pollinated flowers, i.e. higher ovule abortion rate (+21%), higher fruit set (+44%) and higher fruit weight (+50%). Further, the greater parthenocarpic ability of ‘Marisol’ paralleled higher levels of GA1 in the ovary (+34% at anthesis). ‘Marisol’ ovary also showed higher hexoses and starch mobilization, but lower ABA levels (?64% at anthesis). Self‐pollination did not modify carbohydrates or GA content in the ovary compared to un‐pollination. Results indicate that parthenocarpy in the Clementine mandarin is pollination‐independent with its ability to set depending on the ovary hormone levels. These findings suggest that parthenocarpy in fertile self‐incompatible mandarins is constitutively regulated.  相似文献   

4.
The effect of self pollen on the success of cross pollinations was studied in Campsis radicans (L.) Seem., a species previously considered self-sterile. The application of self pollen to stigmas in combination with or preceding the application of cross pollen markedly reduced the likelihood of fruit production. This effect was not due to the dilution of cross pollen nor to physical blocking of the stigmatic surface, since mixtures of talc and cross pollen were as effective as pure cross pollen in causing fruit production. Pollen tubes produced by self pollen grew at rates similar to those from cross pollen, and penetrated the ovary. The interference caused by self pollen appears to take place in the ovary, although it cannot be stated to what degree it is prezygotic or postzygotic. The marked protandry occurring in C. radicans is presumed to be due at least partly to selection for avoidance of these negative effects on female reproductive success. Up to 33% of viable seeds from mixed self + cross pollinations were sired by self pollen. The term “cryptic self-fertility” is coined to describe this phenomenon where pollination with loads of pure self pollen rarely or never yields fruit, but pollination using mixtures of self and cross pollen yields fruit containing considerable numbers of selfed seed. Estimates of selfing frequency that are based on pollination using loads of purely self pollen will be in error for species possessing cryptic self-fertility.  相似文献   

5.
  • Loss and fragmentation of native vegetation negatively affect crop pollinators and productivity of several crop species. The yellow passion fruit is an excellent model to investigate this issue, because its main pollinators are sensitive to deforestation. Seasonality also influences fruit set of crop species that are pollinated by bees. Climate determines plant flowering patterns and consequently affects pollinator activity. Little is known on effects of pollinators on crop quality in general, and particularly of many tropical fruits that have multiple fruiting seasons throughout the year, such as passion fruit. Our hypothesis is that the distance to the native vegetation and climate seasonality affect the pollination and fruit production of cultivated, hermaphrodite, self‐incompatible, protandrous species that depend on large‐sized bees to set fruit.
  • We observed flowers of the yellow passion fruit in eight areas at different distances (600–4,000 m) from a dry seasonal forest (Caatinga). We compared the frequency of the main floral visitor (pollinators and robbers) visits and fruit set among areas at the beginning and end of the dry and rainy seasons.
  • Xylocopa species were pollinators, and Apis mellifera, Trigona spinipes and a hummingbird were robbers. Xylocopa visits diminished with increasing distance to native remnants, converse to what was observed for the robbers at the beginning of the dry season. Fruit set was higher at the beginning of the dry season. The distance to the forest affected quality of fruits in terms of length, diameter and skin thickness, which all decreased with increase in remnant distance.
  • Our results show that insect pollination is higher in the dry season, increasing profitability and reducing labour costs for the producer. Considering the influence of distance to native vegetation on pollination, robbery and fruit quality, our study reinforces the necessity for conservation of native vegetation remnants.
  相似文献   

6.
  • Individuals of Aechmea bracteata show inflorescences with red scape bracts and odourless, yellow, tubular diurnal flowers, with closely arranged sexual organs, producing a large amount of fruits.
  • In order to investigate the reproductive system of this species, a suite of characters was assessed: phenology, floral morphology and biology, nectar production dynamics, and fruit and seed production and germination, as a result of controlled pollination crosses. The study was conducted during two flowering seasons in wild populations in Yucatán, Mexico.
  • Results suggest an annual flowering pattern with one flowering peak; flowers were diurnal, showing partial dichogamy (protandry)‐herkogamy, anthers and stigma become mature before floral aperture, which could lead to self‐pollination, nectar is produced during anthesis, varying in volume and total sugar concentration during the day; fruits and seeds were produced in all experimental crosses (cross‐pollination, obligated cross‐pollination, assisted and unassisted selfing, geitonogamy and apomixis), as well as high percentage seed germination.
  • Several species of Aechmea are reportedly self‐compatible and autogamous, as suggested by results of selfing and non‐assisted selfing crosses, but these results are negated by the presence of apomixis, indicating that the species is apomictic. This is the first report of this breeding system for subgenus Aechmea and the sixth for Bromeliaceae. Polyembryony is here suggested for the first time in this genus and family based on the fact that more seeds were recorded that expected based on ovule numbers. Finally, when performing experimental crosses, estimating reproductive success based on number of seeds is a better approach than number of fruits, due to the effect of pseudogamy.
  相似文献   

7.
Insect pollination plays a vital role for the yield of many crops, such as apples, strawberries and coffee, which are economically significant commodities on the global market. Yet, knowledge about the role of insect pollination is lacking for many cash crops that support the livelihoods of small-scale farmers in developing countries.To assess if yields of watermelon are pollen limited, we conducted a supplemental hand-pollinated experiment (using a pollen mixture of cross and self-pollen) in 13 small-scale farms in an agricultural landscape in the Kilimanjaro and Arusha regions in northern Tanzania. We assessed fruit set, fruit abortion and weight of the mature fruits stemming from hand pollinated and control flowers. To check if differences in yield responses between hand-pollinated and control treatments depended on resource availability, we also accounted for local soil conditions.We found that hand pollination (i) increased the probability of fruit initiation by 30%, (ii) reduced the probability of fruit abortion by 13%, (iii) increased the probability of flowers developing into mature fruits by 42% and (iv) increased average fruit weight by 1.3 kg (±0.15 SE). Our results indicate that our system is pollen limited, due to insufficient visitor frequency and/or inefficient pollinator species.Fruit initiation and fruit weight were positively related to soil carbon, irrespective of treatment. The influence of soil moisture was not consistent across the measured responses, and differed between hand-pollinated and the control treatments.We suggest that farmers in our focal area should focus on improving the quality of the landscape to sustain and enhance healthy pollinator communities ultimately improving yields. We also suggest that farmers should continue current practices with respect to fertilization. The role of soil moisture on fruit initiation and maturation should be investigated to ensure that the positive effects of pollen is not hindered by soil moisture conditions.  相似文献   

8.
 We conducted an experiment in a natural population of Alstroemeria aurea, a clonal perennial, to determine (1) if reproduction was resource limited, and (2) if fruits would be selectively filled based on differences in pollination intensity when pollen loads were adequate for full seed set. Under these conditions, differences in pollination intensity are unlikely to affect seed number, but could affect seed quality, providing an interesting test of the gametophytic competition hypothesis. To test for resource limitation, percent fruit maturation, number of seeds per fruit and average seed weight were compared to paired controls for ramets in which all but one fruit was removed. To test the effect of pollination intensity on selective resource allocation, three types of pollination treatments were performed: (1) all flowers of the single inflorescence received a low pollen load, (2) all flowers received a high pollen load, (3) alternate flowers of the inflorescence received either a high or a low pollen load. We determined the percentage of fruit that reached maturity, counted the number of seeds and ovules and calculated the average seed weight for all capsules in each treatment. Resources appeared to limit reproduction in this population since seed number and weight were significantly higher than in controls when competing capsules were removed. At the whole ramet level, a four fold difference in pollen loads had no significant effect on any of the parameters measured. However, when pollination intensity varied within an inflorescence, the number of seeds per fruit increased by about 10% in flowers that received the higher pollen load. We observed the same trend in each of 2 years, but the increase was significant in only 1 year. The differences, although not great, were only slightly smaller than when all competing fruits were removed, and were consistent with selective resource allocation based on pollination intensity independent of seed set. Received: 28 September 1997 / Accepted: 30 April 1998  相似文献   

9.
Amphicarpy is a fascinating reproductive strategy, defined as fruit produced both below the soil surface and as aerial fruit on the same plant. Trifolium polymorphum is a grassland species subject to herbivory that combines amphicarpy with vegetative reproduction through stolons. Underground flowers have been described as obligate autogamous and aerial ones as self‐compatible allogamous, with aerial floral traits favouring cross‐pollination. In the present work we performed different pollination treatments on aerial flowers to analyse rates of pollen tube development and offspring fitness, measured as fruit set, seed production and germination percentage. This last variable was compared to that of seeds produced underground. No significant differences were found between fruit set in self‐ and cross‐pollinations. Seed production was higher in self‐pollinations, which is consistent with the higher rate of pollen tube development observed in self‐crosses. Spontaneous self‐pollination is limited in aerial flowers; thus pollen transfer by means of a vector is required even within the same flower. Germination tests showed that aerial seeds produced after self‐ and cross‐pollination did not differ in fitness, but underground seeds had higher germination percentage than aerial ones. Thus, we conclude that T. polymorphum has a mixed mating system. In grasslands with heavy grazing pressure, clonal propagation and underground seed production ensure persistence in the field. An intermediate level of selfing in aerial flowers ensures offspring, but morphological (herkogamy) and functional (dicogamy) floral traits maintain a window to incorporate genetic variability, allowing the species to tolerate temporal and spatial pressures.  相似文献   

10.
延迟自动自交和欺骗传粉吸引在被子植物多数类群中有相关报道,但是至今没有发现两种繁育策略在同一物种中共存现象。本研究通过对照试验检测新西兰岩石百合雄蕊附属物和花冠闭合运动是否分别具有欺骗吸引和延迟自交功能。研究结果表明,新西兰岩石百合黄色的雄蕊附属物拟态花粉(或花药),约93%的昆虫访花行为源自黄色花药附属物的欺骗吸引,雄蕊附属物的报酬拟态功能有效提高昆虫拜访频率并促进异交。同时,研究发现新西兰岩石百合花期结束时花瓣闭合促使雌雄隔离距离的缩小,花瓣自然闭合的花朵平均结籽数(20.62)显著高于闭合前去雄处理花朵(11.79)。我们的结果表明延迟自动自交与欺骗传粉吸引两种繁育策略在新西兰岩石百合中共存。  相似文献   

11.
The genus Jacaranda shows notable karyotype stability and a prevailing self‐sterile breeding system with evidence of late‐acting self‐incompatibility in several species. However, some studies have indicated self‐compatibility in J. mimosifolia, a species cultivated worldwide in tropical and subtropical areas. Jacaranda cuspidifolia is a closely related species with natural distribution broadly overlapping with that of J. mimosifolia, and manual heterospecific pollination studies have indicated that these species are interfertile, but there is no report on the breeding system of the former. In this study, we used hand‐pollination experiments, pistil longevity, epi‐fluorescence and histological analysis of post‐pollination events to determine the breeding system of J. cuspidifolia. We also employed intra and interspecific crosses and seed germination tests to reevaluate the breeding system of J. mimosifolia and the inter‐fertility between the two species. Some fruits were initiated from self‐pollinated pistils in J. mimosifolia, but none of them reached maturity. On the other hand, complete absence of fruit development by self‐pollination was verified in J. cuspidifolia, while in situ pollen tube growth and histological analysis of post‐pollination events in selfed pistils revealed the characteristic ovule penetration, fertilization and endosperm initiation also observed in other bignoniaceous species with late‐acting self‐incompatibility. Low outbreeding barriers seem to operate between these species because reciprocal interspecific crosses and hybrid seed germination tests indicated they are bilaterally interfertile. However, fruit/seed production and seed germinability were significantly lower when pistils of J. cuspidifolia were pollinated with pollen of J. mimosifolia, compared with crosses in the opposite direction, which indicates a partial unilateral incompatibility. This result is discussed in the context of the possible occurrence of self‐compatibility in J. mimosifolia. The low level of incongruity operating between the two species also points to their recent evolutionary divergence.  相似文献   

12.
刘金  夏齐平  王建  李真  邵剑文 《植物研究》2018,38(2):232-237
安徽羽叶报春是我国特有的一种珍稀濒危花卉。论文对自花授粉在其花色选育中的应用进行了初步研究。结果表明:安徽羽叶报春自花授粉亲和性较高,平均结籽数可达36.03粒/果,能达到正配授粉结籽数的71.11%(正配授粉结籽数为50.69粒/果),而且自花授粉种子也基本能正常萌发,萌发率为41.13%,达到正配授粉种子萌发率的57.98%。花色分析显示自花授粉子代花色R值比重均值(即红色成分,为0.382)显著高于其亲本群体及正配授粉子代的均值(均为0.375左右)。因此安徽羽叶报春自花授粉虽存在一定的衰退现象,但它有利于花色的选育和纯合品系的获得,在其花色的选育过程中应加以重视和利用。  相似文献   

13.
Fruit size within a tomato (Lycopersicon esculentum Mill.) truss depends on both fruit position in the truss and the time of pollination among fruits. In the natural pollination sequence a difference of 5 days in the pollination of proximal and distal flowers results in significant final size differences between proximal and distal fruits. These final size differences were eliminated when all flowers were pollinated simultaneously. At anthesis proximal ovaries have higher cell numbers than distal ovaries but the cell division activity and cell enlargement in both positions was similar in the first 10 days of fruit growth. Simultaneous pollination resulted in lower cell numbers in proximal but higher cell numbers in distal fruits compared to control fruits.Hormone levels in different sized fruits were measured using radioimmunoassays. Cytokinin concentration during the cell division period indicated a possible role in the regulation of cell division. With other hormones no obvious correlations were found. The results are discussed in relation to factors determining final fruit size in tomato.  相似文献   

14.
A homozygous self-compatible almond, originated from self-fertilization of a self-compatible genotype and producing a reasonable yield following open pollination, exhibited a very high fruit drop rate when self-pollinated. To investigate whether fruit dropping in this individual is related to an abnormal development of the embryo sac following self-fertilization, histological sections of ovaries from self and cross-pollinated flowers were observed by light microscopy. Additionally, the presence of pollen tubes in the ovary and fruit set were determined for both types of pollination. Despite pollen tubes reached the ovary after both pollinations, differences in embryo sac and endosperm development after fertilization were found. Thus, while for cross-fertilized ovules a pro-embryo and an endosperm with abundant nuclei were generally observed, most self-fertilized ovules remained in a previous developmental stage in which the embryo sac was not elongated and endosperm nuclei were absent. Although 30 days after pollination fruit set was similar for both pollination types, at 60 days it was significantly reduced for self-pollination. These results provide evidence that the high fruit drop in this genotype is the consequence of a disrupted development of the endosperm, what could be an expression of its high level of inbreeding.  相似文献   

15.
Eschweilera nana is pollinated by a guild of pollinators consisting of mostly bees. Effective pollinators are large bees able to force their way into the closed androecium to access nectar. The morphology of the flowers diminishes self pollination and promotes cross-pollination. Although many pollinators make diurnal visits to the flowers, fruit set was very low in comparison with the number of flowers produced. Breeding system tests yielded only two fruits, one produced by xenogamy and another one in the control test. The results of this study are consistent with studies of other Cerrado plants pollinated by guilds of insects and support the conclusion of other pollination studies of Lecythidaceae that fruit set is low in comparison with the high numbers of flowers produced.  相似文献   

16.
We show experimentally that several types of selfing occur simultaneously in Drosophyllum lusitanicum: prior, competitive, insect-facilitated, delayed and geitonogamous. In addition, we report evidence of cleistogamy in the flower bud. All types of selfing were successful in producing fruits and seeds; however, geitonogamy did not occur uniformly throughout the flowering period in this species. We also report the absence of cryptic self-incompatibility: the germination rate and pollen tube growth rate of cross pollen were no greater than those of self pollen when both types were placed on stigmas of the same flower (mixed pollination). There was a tendency for self pollen to be more vigorous than cross pollen but it just failed to reach significance.  相似文献   

17.
Although fruit set and development are induced by applications of gibberellins, final fruit weight of gibberellin-induced parthenocarpic fruit is often less than that of pollinated fruit. We examined changes in the activities of sucrose-metabolizing enzymes and sugar accumulation in developing fruits of cultivated blueberry (Vaccinium ashei Reade) and their correlation with fruit growth upon pollination or exogenous applications of gibberellic acid (GA3). The objective was to determine if differences in fruit growth could be attributed to differences in enzyme activities and subsequent sugar accumulation in fruits. The fruit development period of GA3-treated fruits was 15 days longer than that of pollinated fruits. At maturity, GA3-treated fruit accumulated an average of 180 mg dry weight while pollinated fruit accumulated 390 mg dry weight. Dry weight accumulation in nonpollinated fruits was negligible and these fruits abscised by 45 days after bloom (DAB). The total carbon (C) cost (dry weight C + respiratory C) for fruit development was 109 and 244 mg C fruit-1 for GA3-treated and pollinated fruits, respectively. Hexose concentration increased to 100 mg (g fresh weight)-1 at ripening in both GA3-treated and pollinated fruits. Nonpollinated fruits reached a maximum hexose concentration at 45 DAB. Sucrose phosphate synthase (EC 2.4.1.14) and sucrose synthase (EC 2.4.1.13) activities reached a maximum of ≤5.0 μmol (g fresh weight)-1 h-1 in both GA3-treated and pollinated fruits. Soluble acid invertase (EC 3.2.1.26) activity increased to about 60 μmol (g fresh weight)-1 h-1 in both GA3-treated and pollinated fruits at ripening, while in nonpollinated fruits, a maximum soluble acid invertase activity of 0.12 μmol (g fresh weight)-1 h-1 was measured at 24 DAB. Insoluble acid invertase activity declined during the early stages of fruit growth and remained relatively low throughout fruit development. Neutral invertase activity was low throughout development, increasing to 5 μmol (g fresh weight)-1 h-1 at ripening in GA3-treated and pollinated fruits. Our studies demonstrate that blueberry fruit development does not appear to be limited by sucrose metabolizing enzyme activity and/or the ability to accumulate sugars in either GA3-treated or pollinated fruits.  相似文献   

18.
19.
  • Flowering plants often depend on the attraction of biotic pollinators for sexual reproduction. Consequently, the emergence and maintenance of selected floral attributes related to pollinator attraction and rewarding are driven by pollinator pressure.
  • In this paper we explore the effect of pollinators, rainfall, temperature and air humidity on the reproduction of a Brazilian terrestrial orchid, Cranichis candida based on data of phenology, flower resources, olfactory and visual attraction cues, pollinators and breeding system.
  • The flowers of C. candida are strongly protandrous and pollinated by workers of the social native bee Tetragonisca angustula. The bees collect labellar lipoidal substances (wax scales), which are transported to the nest. The lipoidal substance is composed of sterols, hydrocarbons and terpenes. The last presumably protects the bees and their nests against pathogens and other arthropods. C. candida sets fruits through biotic self‐ and cross‐pollination, and spontaneously due the action of raindrops on flowers.
  • Our results indicate that in C. candida, although rain‐mediated spontaneous self‐pollination happens, fructification mediated by biotic pollinations also occurs, which may result in fruit set by cross‐pollination. A mixed pollination system must result in higher genetic variability when compared to species whose fruits are produced entirely by self‐pollination. On the other hand, autogamy is a form of reproductive assurance, and has commonly evolved where pollination services are rare or absent.
  相似文献   

20.
Delayed autonomous pollination and deceptive pollination are assumed to be relatively common in flowering plants, but no species have been reported to use both of these cunning reproductive strategies. In this study, we examined whether delayed selfing and mimicry were used concurrently in Arthropodium cirratum. Flowers of A.cirratum were manipulated to assess whether their stamen appendages and corolla closing movements were functional in deceptive pollination and delayed selfing, respectively. Our results indicated that anther or pollen imitation of the yellow stamen appendages contributed to 93 per cent of successful mimetic attraction, and this mimicry was an important driver of cross pollination of the species. In addition, we observed closure of the perianth relocated the stamens over the stigma at the end of anthesis, which significantly increased the average seed number per fruit of intact flowers over flowers emasculated before closure (20.62 versus 11.79). Our findings confirmed the coexistence of delayed autonomous self pollination and deceptive pollination in A.cirratum. Our results also suggested that delayed selfing could add fitness benefits for this mimetic attraction species.  相似文献   

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