EFFECTS OF POLLINATION INTENSITY IN CAMPSIS RADICANS

I examined effects of pollination intensity on fruit, seed and seedling characteristics in Campsis radicans, and joint effects of pollen donor and pollination intensity on fruit production. Large pollen loads were more likely to initiate fruit production than small pollen loads, and the former fruits contained more seeds and a greater total seed mass. No further increases in seed number or mass occurred for pollen loads above 4,000 grains. The weight of individual seeds was unaffected by pollen load. Effects of pollen donor were generally larger than effects of pollen load, and fruit production from small loads of pollen from one donor were sometimes equal to fruit production from larger pollen loads from another donor. The ratio of pollen grains deposited to resultant seeds increased with pollen load, and several explanations are proposed. Seeds from heavy pollinations emerged better than seeds from light pollinations, but did not differ in speed of germination or in the performance of seedlings up to 126 days. The emergence differences are probably due to differing intensities of pollen tube competition.     

The effects of pollen diversity on plant reproduction: insights from apple

For many plants, the number of pollen genotypes deposited on a flower’s stigma is positively related to fruit maturation and seed number; however, the mechanisms underlying this effect are less understood. Here we examined whether diversity of pollen (1, 3, or 5 donors) affects reproductive success in self-incompatible apple (Malus × domestica). Using paternity analysis, we then assessed the siring rate of individual donors to test whether diversity effects are related to the presence of a superior pollen donor or to donor × donor interactions. Increasing the diversity of compatible pollen enhanced seed number and reduced seed abortion in some but not all recipient genotypes. This effect was associated with an increased number of sires per fruit and non-random siring success among pollen donors. Two donors had consistently high siring rates, regardless of recipient genotype; however, the siring success of pollen donors was not correlated with their siring success in single-donor pollinations. Rather, siring success was affected by the identity of other pollen genotypes present on the stigma. Our results therefore suggest that the effects of pollen diversity are variable but may enhance fecundity by fostering interactions between pollen donors.     

NONRANDOM MATING IN WILD RADISH: VARIATION IN POLLEN DONOR SUCCESS AND EFFECTS OF MULTIPLE PATERNITY AMONG ONE- TO SIX-DONOR POLLINATIONS

Nonrandom mating in plants may involve differential success of self- vs. outcross pollen, of pollen from relatives vs. nonrelatives, and of pollen from several compatible donors. Of these, the last is least understood. Wild radish plants were crossed with six pollen donors in all possible combinations to investigate differences in pollen donor performance and to compare multiply sired fruits with different numbers and identities of fathers. Pollen donors differed in number of seeds sired, position of seeds sired within fruits, and mass of seeds sired. Performance in single pollination was not a good predictor of performance in mixed pollination. Performance in two-donor pollinations was a better predictor of the outcome of multidonor pollinations. Multiply sired fruits were selectively filled, but not all multiply sired fruits were equal. Both the number and identity of donors affected fruit filling. These results and others with wild radish suggest that variation in pollen donor ability to sire seeds is relatively common in wild radish. Since wild radish plants in the field typically receive pollen from several donors, there may be considerable opportunity for selection at this stage of the life cycle in wild radish.     

Pollen load size, reproductive success, and progeny kinship of naturally pollinated flowers of the tropical dry forest tree Pachira quinata (Bombacaceae)

Several studies have demonstrated, using controlled pollinations, that the number and identity of pollen grains deposited onto a flower's stigma affect the reproductive success of plants. However, few studies have shown this relationship under conditions of natural pollination. Using the tropical dry forest tree Pachira quinata, we evaluated the relationship between the number of microgametophytes per pistil and the number of sires with respect to the production of fruits and seeds in a natural population of Pachira quinata. Our study demonstrates that fruit and seed production are directly related to the number of microgametophytes per pistil in natural populations of P. quinata. Only 6% of the marked flowers developed into mature fruits and 10% of the marked flowers initiated fruits but later aborted them. A mean of 23 pollen grains were required to produce a seed. Flowers with >400 pollen grains on the stigma always developed into mature fruits, whereas flowers that received <200 grains never matured fruits. Half of the pollen grains transferred to a flower stigma germinated and developed pollen tubes to the base of the style. The number of pollen grains on a stigma explained 34% of the variation in seed number per fruit, and the number of seeds produced per fruit is positively correlated with the size of the seeds. The population of P. quinata studied is predominantly outcrossing, and seeds within fruits are sired by one or a few donors. The total seed crop within trees was sired by three to five donors. Our study examined the implications of the variation in size of microgametophyte loads per pistil with respect to the breeding system and the paternity of progeny under natural conditions. The competitive ability of pollen and pollen tube attrition are important factors regulating fruit production in P. quinata.     

FERTILIZATION DYNAMICS AND PARENTAL EFFECTS UPON FRUIT DEVELOPMENT IN RAPHANUS RAPHANISTRUM: CONSEQUENCES FOR SEED SIZE VARIATION

Seed weight varies significantly within and among fruits of wild radish (Raphanus raphanistrum). To determine sources of this variation, we studied fertilization and seed development following controlled pollinations. Within fruits, central ovules were fertilized prior to distal ovules and attained greater seed size. Ninety-seven percent of the variation in mean seed wt per fruit was explained by an analysis of variance incorporating parental effects, pollination date, and the number of seeds per fruit. We document strong maternal effects on the number of ovules per ovary, the number of fertilized ovules per ovary, the number of seeds per fruit, and mean individual seed wt per fruit. Across females, pollen donor had a slight but significant effect on seed wt; no paternal effects on fertilization rate, zygote number, or seed number per fruit were detected. Within females, with one exception, pollen donor had no significant effect on these components of seed development. Stronger maternal main effects may be due to donor x recipient interactions, cytoplasmic factors, the genetic inequity within triploid endosperm, and/or strict maternal control over resource allocation. The large maternal effects relative to paternal effects may limit the rate at which natural selection acts on paternal traits expressed prior to seed maturation.     

The breeding system of Lycium cestroides: a Solanaceae with ovarian self-incompatibility

To determine the breeding system of Lycium cestroides,several treatments were performed: self-, cross-, and geitonogamous pollinations, autonomous self-pollination, and a control (flowers exposed to natural pollinators). Production and quality of fruits and seeds as well as pollen tube growth were evaluated for each treatment. Experimental pollinations indicate that L. cestroides is self-incompatible since fruits were obtained only under cross-, and open-pollination treatments. However, in self- and geitonogamous hand pollinations, as well as in autonomous self-pollination, pollen tubes developed successfully and reached the ovules. The speed of pollen tube growth did not differ significantly among the different hand-pollinated flowers (cross-, self-, and geitonogamous). These facts indicate the presence of an ovarian self-incompatibility system. Significant differences were observed in fruit set, fruit size, and seed number per fruit between cross-pollinated flowers and open pollination (control). These results could be explained in terms of quantity and quality of pollination in each case. Received: 2 November 2000 / Revision accepted: 26 January 2001     

Effects of parentage,prior fruit set and pollen load on fruit and seed production in Campanula americana L

Summary We conducted a controlled crossing experiment to examine the effects of maternal and paternal parentage, the size of the pollen load, and prior fruit production on the proportion of flowers that set fruit, seed number per fruit and seed weight in a natural population of Campanula americana. Effects due to the maternal parent were large for all measures of fruit and seed production, while the paternal parent had a significant effect only upon mean seed weight. As the number of prior fruits on the maternal plant increased the probability that a flower would produce a mature fruit, the number of seeds per fruit, and total seed weight per fruit all decreased. We found no effect of the size of the pollen loads used in this study on fruit or seed production. These results are consistent with those of other studies that suggest in natural plant populations maternal effects, especially environmental maternal effects, can have an overwhelming effect on fruit and seed production and on seed characteristics.     

Sequential variation in the components of reproductive success in the distylousJasminum fruticans (Oleaceae)

A 2-year study of three natural populations of the distylousJasminum fruticans showed that mean fruit and seed production were significantly greater in shortstyled plants (thrums) than in long-styled plants (pins). In this study, we investigated the role of four sequential factors which may differentially influence fruit and seed set in the two floral morphs: (1) differences in flowering phenology, (2) a limitation of pollen transfer towards pins, (3) a differential capacity of the two morphs to act through famale and male function and (4) differential fruit abortion in the two morphs. Fruit set was significantly influenced by differences in flowering phenology although there were no differences in flowering time between the two morphs. supplementary pollinations in a natural population significantly increased fruit set and reduced the difference in fruit set between the two morphs in relation to controls, indicating a limitation on pollen transfer which was most severe towards pin stigmas. In reciprocal crosses, seed set was significantly dependent on the paternal and maternal identity of the pin parent. There was no significant variation among thrums for their performance as male or female parent. Furthermore, individual pin plants with relatively high percentage seed set as female parents gave poor seed set as male parents and vice-versa. Whereas fruit removal had no effect on seed number in thrum plants, a greater proportion of viable seeds were produced on pin plants which were left to naturally mature their fruits than on pins which had fruits artificially removed, suggesting the occurrence of selective fruit abortion in pins but not in thrums. The initially greater maternal fitness of thrums due to their greater success as pollen recipients may thus be opposed by increased viable seed set in the pins due to factors acting after the pollination stage. The relative reproductive success of floral morphs in the distylousJ. fruticans is thus differentially influenced by ecological factors occurring at different stages of the reproductive process.     

THE INFLUENCE OF THE MATING SYSTEM ON SEED SIZE VARIATION IN CRINUM ERUBESCENS (AMARYLLIDACEAE)

We present evidence that extreme seed size variation in fruits of Crinum erubescens (range: 0.1 to 66.5 g per seed) occurs when mating pairs are inbred, either from selfing or biparental inbreeding. Several relatively uniform seeds of intermediate size are produced when pollen from several pollen donors is applied simultaneously to a flower. Selfed fruits and some fruits pollinated with a single pollen donor produce both large and small seeds, although selfed fruits produce fewer seeds than outcrossed fruit. These results are contrary to the hypothesis that variation in seed size is attributable to either pollen competition or differential allocation of maternal resource to seeds of different genotypes.     

Mixed pollen load and late‐acting self‐incompatibility flexibility in Adenocalymma peregrinum (Miers) L.G. Lohmann (Bignonieae: Bignoniaceae)

• Mixed cross and self‐pollen load on the stigma (mixed pollination) of species with late‐acting self‐incompatibility system (LSI) can lead to self‐fertilized seed production. This “cryptic self‐fertility” may allow selfed seedling development in species otherwise largely self‐sterile. Our aims were to check if mixed pollinations would lead to fruit set in LSI Adenocalymma peregrinum, and test for evidence of early‐acting inbreeding depression in putative selfed seeds from mixed pollinations.
• Experimental pollinations were carried out in a natural population. Fruit and seed set from self‐, cross and mixed pollinations were analysed. Further germination tests were carried out for the seeds obtained from treatments.
• Our results confirm self‐incompatibility, and fruit set from cross‐pollinations was three‐fold that from mixed pollinations. This low fruit set in mixed pollinations is most likely due to a greater number of self‐ than cross‐fertilized ovules, which promotes LSI action and pistil abortion. Likewise, higher percentage of empty seeds in surviving fruits from mixed pollinations compared with cross‐pollinations is probably due to ovule discounting caused by self‐fertilization. Moreover, germinability of seeds with developed embryos was lower in fruits from mixed than from cross‐pollinations, and the non‐viable seeds from mixed pollinations showed one‐third of the mass of those from cross‐pollinations.
• The great number of empty seeds, lower germinability, lower mass of non‐viable seeds, and higher variation in seed mass distribution in mixed pollinations, strongly suggests early‐acing inbreeding depression in putative selfed seeds. In this sense, LSI and inbreeding depression acting together probably constrain self‐fertilized seedling establishment in A. peregrinum.

     

RELATIVE SUCCESS OF SELF AND OUTCROSS POLLEN COMPARING MIXED- AND SINGLE-DONOR POLLINATIONS IN AQUILEGIA CAERULEA

Flowers frequently receive both self (S) and outcross (OC) pollen, but S pollen often sires proportionally fewer seeds. Failure of S pollen can reflect evolved mechanisms that promote outcrossing and/or inbreeding depression expressed during seed development. The relative importance of these two processes was investigated in Aquilegia caerulea, a self-compatible perennial herb. In the field I performed single-donor (S or OC) and mixed-donor (S plus OC) pollinations to compare the relative success of both pollen types at various stages from pollen germination to seed maturity. Single-donor S pollinations produced significantly fewer and lighter seeds (x decrease = 12% and 3%, respectively) than OC pollinations. Abortion rates differed by an average of 38% whereas fertilization rates differed by only 5%, indicating that most differences in seed number arose postzygotically. This suggests that inbreeding depression was responsible for most failure of S pollen. One prezygotic effect measured was that 10% fewer S than OC pollen tubes reached ovaries after 42 hr, suggesting S pollen might fertilize proportionately fewer ovules after mixed pollination. Using allozyme markers, I found mixed-donor pollinations produced significantly more and heavier outcrossed than selfed seeds. However, the proportion of selfed seed, fertilized ovules, and aborted seeds for mixed-donor fruits were each predictable from pollen performance in single-donor fruits, suggesting that differential paternity is best explained by inbreeding depression during seed development. Even given these similarities between mixed- and single-donor fruits in the relative performance of S and OC pollen, both individual seed weight and seed set were significantly higher in multiply-sired fruits.     

EFFECT OF MALE POLLEN DONOR AND FEMALE SEED PARENT ON ALLOCATION OF RESOURCES TO DEVELOPING SEEDS AND FRUIT IN CHAMAECRISTA FASCICULATA (LEGUMINOSAE)

In Chamaecrista fasciculata, fruit abortion levels are high and seed mass is highly variable, necessary preconditions for differential resource allocation of the female to seed and fruit sired by different males. This study investigated the relative role of pollen donor and seed parent on the allocation of resouces to developing seed and fruit, and assessed the role of genetic relatedness in contributing to any observed paternal effect in C. fasciculata. In addition, pollen donor effects were contrasted to within-seed parent sources of variation in resource allocation due to pollination date and ovule position in the pod. Plants collected from the field were brought to a greenhouse where single-donor crosses were conducted controlling for pollen donor source and interplant distance, a measure of genetic relatedness. Seed mass, number of seed/fruit, fruit maturation time, and fruit abortion rate were measured as indicators of resource allocation to developing seed and fruit. Variation in resource allocation was largely determined by the seed parent. Pollen donor effects were limited to differences between self vs. non-self pollinations, suggesting that inbreeding depression following mating events between related individuals is the source of any variation among pollen donors on differential resource allocation to developing seed and fruit. Once the effect of inbreeding was removed, however, pollination date and ovule position played larger roles than pollen source. Since there was no detectable variation among male pollen donors in their ability to accrue resources from the female seed parent apart from inbreeding effects, it is concluded that the opportunity for postzygotic mate choice is limited in C. fasciculata.     

The effects of pollen load size and donor diversity on pollen performance, selective abortion, and progeny vigor in Mirabilis jalapa

The influence of pollen competitive environment on pollen performance (pollen germination, stigmatic penetration, and pollen tube growth rate), the maturation or abortion of initiated fruit, seed size, and seedling vigor was explored by manipulating the size and diversity of stigmatic pollen loads on Mirabilis jalapa. All aspects of pollen performance significantly increased with the number of pollen grains on a stigma or pollen tubes in a style, but was not influenced by the diversity of pollen donors. Plants tended to mature single-ovulate fruits that came from flowers where pollen load size and diversity were greatest and aborted those where these were lowest. No plants from seeds resulting from pollinations with a single pollen grain survived, but other fitness measures were mostly determined by maternal plant. The data suggest that pollen performance is influenced by pollen competitive environment, and both the genetic diversity of the pollen load and number of competing pollen tubes are important determinants of seed/fruit abortion.     

Does multiple paternity affect seed mass in angiosperms? An experimental test in Dalechampia scandens

Flowers fertilized by multiple fathers may be expected to produce heavier seeds than those fertilized by a single father. However, the adaptive mechanisms leading to such differences remain unclear, and the evidence inconsistent. Here, we first review the different hypotheses predicting an increase in seed mass when multiple paternity occurs. We show that distinguishing between these hypotheses requires information about average seed mass, but also about within‐fruit variance in seed mass, bias in siring success among pollen donors, and whether siring success and seed mass are correlated. We then report the results of an experiment on Dalechampia scandens (Euphorbiaceae), assessing these critical variables in conjunction with a comparison of seed mass resulting from crosses with single vs. multiple pollen donors. Siring success differed among males when competing for fertilization, but average seed mass was not affected by the number of fathers. Furthermore, paternal identity explained only 3.8% of the variance in seed mass, and siring success was not correlated with the mass of the seeds produced. Finally, within‐infructescence variance in seed mass was not affected by the number of fathers. These results suggest that neither differential allocation nor sibling rivalry has any effect on the average mass of seeds in multiply sired fruits in D. scandens. Overall, the limited paternal effects observed in most studies and the possibility of diversification bet hedging among flowers (but not within flowers), suggest that multiple paternity within fruits or infructescence is unlikely to affect seed mass in a large number of angiosperm species.     

VARIATION IN POLLEN SIZE,FERTILIZATION ABILITY,AND POSTFERTILIZATION SIRING ABILITY IN ERYTHRONIUM GRANDIFLORUM

The mean volume of pollen grains and total pollen production varied both within and among plants of Erythronium grandiflorum. The second flowers of two-flowered plants tended to produce smaller and fewer grains than first flowers, but there was no overall relationship between mean pollen grain size and production per flower. I evaluated the effects of pollen size differences within and among plants on two components of male reproductive success: pollen tube growth and postfertilization siring ability. Pollen tubes grown in media were longer for second flowers, but were not correlated with the mean size of pollen grains, suggesting that (1) internal resource content of pollen (i.e., carbohydrates plus lipids) was not associated with the hydrated size of pollen, and that (2) pollen from second flowers contained more resources. I analyzed the growth rate and the fertilization ability of pollen growing in styles. Growth rate differed among donors and recipients, but no effects of pollen or donor characters (i.e., pollen production, grain size, and flower position) were detected. In single donor pollinations, pollen size was negatively correlated with fertilization ability across donors, and positively correlated with postfertilization siring ability of donors. A second experiment used pairs of donors; within-plant differences in pollen size and flower position had effects similar to the single donor experiment on fertilization ability, but among-plant differences were not significant. The results corroborate earlier experiments that suggest that the growth of pollen tubes in the style is probably controlled by the recipient, since donor characters had minimal effects on pollen fertilization ability. Postfertilization siring ability was not affected by within-plant differences in mean grain size and production. For among-donor differences, the number of seeds set for each donor was positively correlated with the mean grain volume, and when a donor producing large pollen fertilized ovules in an ovary, there was increased seed abortion for seeds in the same ovary sired by a second donor. In addition, the total number of seeds produced by a fruit was decreased when both donors had large pollen, apparently due to increased postfertilization abortion. Postfertilization processes appear to be influenced by paternal differences that are expressed through competition among developing seeds for maternal resources.     

Breeding system of tristylous Eichhornia azurea (Pontederiaceae) in the southern Pantanal, Brazil

The breeding system of Eichhornia azurea (Pontederiaceae) has been described as being both self- and heteromorphic incompatible based on crossing experiments performed on plants grown in an experimental garden. We studied the breeding system of tristylous E. azurea population under natural conditions in the Pantanal wetlands, Brazil. Controlled pollinations were conducted using 35 individuals of each floral morph. Legitimate pollinations produced more fruits than self- and illegitimate pollinations, except for the mid-styled morph which was highly self- and heteromorphic compatible. The number of seeds per fruit was higher under legitimate pollinations than in the other treatments, but self- and illegitimate pollinations produced more fruits and seeds in the Pantanal than for individuals of E. azurea in other populations. The higher fruit and seed production resulting from legitimate pollinations corroborate previous studies, but self-compatibility of mid-styled plants was not previously reported. Overall results indicate a partially self- and heteromorphic compatible system for this species in the Pantanal.     

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.     

Effects of pre-dispersal selection on offspring growth and survival in Erythronium grandiflorum

Effects of pre-seed-dispersal processes on offspring vigor were examined in Erythronium grandiflorum using manipulations of the number of pollen donors contributing to the pollen pool and comparisons of means and variances in offspring growth measurements. There were no effects of the number of donors on measures of pollen-tube growth, ovule abortion, seed set, mean seed weight, or seedling germination. Seeds from pollinations with only one donor produced corms that averaged 5% lighter after one season of growth and had lower overall survival after three years compared to corms from pollinations with either three or ten donors. Patterns of within- and among-family variance estimates for the different treatments were consistent with the hypothesis that less-vigorous offspring were eliminated prior to seed dispersal in the multiple-donor treatments. The difference in the growth of offspring from different treatments was apparently not due to pollen competition because pre-zygotic attrition of pollen tubes led to incomplete fertilization of ovules. Results from this study suggest that post-fertilization abortion of less-vigorous progeny, perhaps as a consequence of early-acting inbreeding depression, is responsible for the increase in the average vigor of offspring from multiply-sired fruits.     

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.     

文冠果花粉供体的多样性对果实产出的影响

很多植物的花,其柱头上接受的花粉供体多样性数量通常与果实成熟和种子产出有关。关于提高花粉多样性能否增加植物的生殖产出问题,文献中时常有相互矛盾的结论。本研究通过对自交不亲和性植物文冠果(Xanthoceras sorbifolium)进行1、2、3、4种花粉供体传粉实验,调查了不同花粉供体数量对文冠果雌性生殖的影响。结果表明,增加亲和花粉供体的多样性,一定程度上提高了花序上果实的坐果数量,同时也增加了果实中种子的数量及单粒种子重量。对文冠果授以4种亲和性花粉供体后,花序上成熟果实的平均数最多;3种亲和性花粉供体传粉后,每个果实中的种子数最多,单粒种子也最重。如果混合花粉中含有自交花粉,那么果实将败育。除花粉多样性影响雌性生殖产出外,母本基因型也具有重要影响,即增加文冠果种植品系的多样性,将有助于提高果实和种子产量。本研究还讨论了花粉遗传多样性效应、母本交配选择及果实选择性败育假说。