Effect Of Pollen Source Research Articles

Evaluation of viability and germination of pollen grains of three local caprifig cultivars and their effect on some characteristics of fig fruits (Ficus carica L.)

This research was carried out in fig fields in the village of Kafar-Jales, in the north of Syria. The analyses were conducted in the laboratories of the Faculty of Agriculture at Idlib University during the 2022 farming season, to evaluate the viability and germination of three local varieties of Caprifig (Bunduqi, Azraq, Panjani). The morphological characteristics, the date of the exodus of insects (Blastophaga psenes) from male fruits, the quantity of pollen, and the percentage of germination and viability were studied on four nutritive media at a temperature of 27°C. The measurements were taken after 24 h, 48 h, and 72 h. These three pollinators were used to pollinate three varieties of edible figs (white Satehi, Safrawi, and Habashi) to study the effect of pollen source on the productive characteristics of edible fig fruits. The result showed significant superiority of the Bunduqi cultivar over the rest of the cultivars in traits of the fruit’s early ripening, pollen quantity, and date of departure of insects. The Azraq cultivar is found to be superior to Bunduqi and Panjani cultivars in the germination rate of pollen at all stages of the experiment and in all used media. The addition of stigma flower extract in culture media increased germination percentage by 35% for all studied Caprifig cultivars. The addition of 10% sucrose in the cultivation environment increased the percentage of pollen germination by 20%. The cultivars that were inoculated with the Panjani pollinator outperformed the characteristics of the length, diameter, and weight, demonstrating that the fruit’s quality characteristics are affected by the genotype of the pollinator used. The results of this research can be beneficial for both fig growers and plant breeders, as they help to select the best pollinators and contribute to the development and improvement of the quality of the cultivated fig fruits.

Effect of pollen sources on fruit set and quality of edible fig (Ficus carica L.) cv. ‘Bursa Siyahı’

The caprification practice has been used widely in fig cultivation because it affects the yield and quality of fig fruits, a phenomenon known as the ‘xenia effect’. The present study was conducted to investigate the effects of pollen sources on fruit sets and fruit quality in the ‘Bursa Siyahı’ fig cultivar in 2017 and 2018. The eleven male genotypes and five cultivars were used as pollen source. The findings obtained in the present study showed that pollen sources significantly affected fruit set, early fruiting rate, fruit size, ostiole width, skin and flesh thickness, titratable acidity (TA), pH, and soluble solids content (SSC). The fruit set ratio varied from 32.02% (‘16 03 06’) to 76.66% (‘16 08 07’), and fruit weight varied from 77.29 g (‘16 03 06’) to 106.88 g (‘16 00 01’) based on pollen sources. The ostiole diameter ranged from 3.84 mm (‘16 ZF 08’) to 7.67 mm (‘77 00 01’). The skin thickness ranged from 3.01 mm (‘Havran’) to 5.35 mm (‘16 00 01’). The principal component analysis was performed to distinguish the pollen sources for the ‘Bursa Siyahı’ cultivar. The analysis proposed that the most important factors affecting the fig quality can be reduced to five components. Fruit weight (0.958), skin thickness (0.810), flesh l* value (0.821), pH (-0.872), and SSC (0.836) value could be regarded as the characteristic indicators for PC1, PC2, PC3, PC4, and PC5, respectively. The results showed that ‘16 09 10’, ‘16 05 03’, ‘16 08 07’, and ‘16 08 12’ pollen sources are adequate pollinators for the edible ‘Bursa Siyahı’ fig.

The effects of pollen source on the fatty acid profile of Macadamia kernels

Macadamia nuts are an abundant source of the monounsaturated fats (59 %), oleic (50 %−65 %) and palmitoleic acid (12 %−30 %). As macadamia is generally an outcrossing species, this study focuses on the effect of both the maternal (seed parent) and paternal (pollen parent) genotype on the accumulation of the principal fatty acids in macadamia using a controlled 3 × 3 pollination trial. Both the seed parent and pollen parent were observed to significantly impact the fatty acid profile of macadamia nut kernels. In addition, the general combining abilities (GCA) of the parental cultivars and specific combining abilities (SCA) of parental crosses were determined, as well as identifying maternal/paternal combinations that could significantly increase palmitoleic acid and oleic acid, or decrease saturated fat concentration. These results provide evidence for the first time that pollen source has a significant impact on the fatty acid profile of macadamia kernels, and that previous reporting of the fatty acid profiles of macadamia cultivars is likely to be variable, due to the unknown genotype of pollen sources.

Pistil Biology of ‘WA 38’ Apple and Effect of Pollen Source on Pollen Tube Growth and Fruit Set

‘WA 38’ (‘Enterprise’ × ‘Honeycrisp’) is an apple variety that is characterized by a peculiar self-thinning trait in which most of the fruitlets naturally shed within the first 8 weeks after bloom, leaving some clusters empty, but most with 1–2 apples. This study aimed to investigate potential causes for the relatively low fruit set observed in ‘WA 38’ by investigating its flower biology. This study comprised three objectives: (1) To characterize the effective pollination period (EPP) of ‘WA 38’ by studying stigmatic receptivity, pollen tube growth, and ovule longevity in ‘WA 38’ flowers, (2) to compare the pollen tube growth of 5 fully compatible pollinizer varieties in ‘WA 38’ pistils, and (3) to evaluate fruit and seed set resulting from controlled pollinations with 5 fully compatible pollinizer varieties. The results showed ‘WA 38’ EPP was approximately 3.2 days in 2019 and 1.4 days in 2020, and that differences in pollen sources did not attribute significant differences in fertility in ‘WA 38’ flowers. The results of this study suggest mechanisms other than pollination and fertilization, such as competition among fruitlets within a cluster or hormone signaling, may have a stronger impact on ‘WA 38’ fruitlet abscission.

Pengaruh Variasi Pollen Terhadap Karakteristik Kimia Bee pollen

Bee pollen contains high enough nutrition. Bee pollen contains some nutrients such as water, ash, lipid, protein, natural antioxidants, palmitic acid, oleic acid, linoleic acid, and linolenic acid. The high nutrients on bee pollen causes bee pollen to be widely used by many people as a food additive on some food productions. Bee pollen is widely used as a fortificant and substitute material. Bee pollen as a substitute material on the making of crackers. On snack bar making, bee pollen is used as a fortificant material. Bee pollen as a fortificant is also used on the making of milk to increase its nutrients, especially the polyphenols. One of the factors effecting the nutrient contents of bee pollen is the source of pollen. There are two sources of pollens, multiflora and uniflora. The aim of this experiment is to know the effect of pollen sources on water, ash, lipid, protein and crude fiber content in 3 types of commercial pollen in Indonesia. The result is bee pollen from 3 different plants pollen have a significant difference to proximate content including water, ash, lipid, protein, carbohydrate, and crude fiber.
 Keywords: bee pollen, proximate, pollen

Evaluation of Breeding Strategies for Pistachio Male Genotypes Based on Flowering Index, Pollen Traits, and Female Yield Elements

This study was carried out in the Khatam, Yazd province, Iran from the beginning of 2014 to the end of 2015. Phenological traits and pollen properties of some male pistachio genotypes ‘A1’, ‘A2’, ‘A3’, ‘A4’, ‘A5’, ‘A6’, ‘A7’, ‘A8’, ‘A9’, ‘N1’, ‘Mh1’, ‘G1’, ‘M1’, ‘M2’, and ‘F1’ were surveyed. To find the effect of pollen source on the nut traits of the resulting seeds as well as the initial fruit set, Xenia and Metaxenia were evaluated. Moreover, pistillate flowers of the ‘Akbari’ cultivar were crossed with different pollen sources. Results showed that pollen germination of male pistachio genotypes was various. Among all of the pistachio male genotypes, the highest pollen germination percentage was obtained from ‘M1’ (92.66%) followed by ‘Mh1’ (86.66%) and ‘G1’ (86.00%). There were also significant differences between cluster and pollen weight of different pollen sources. Based on our findings, among the studied genotypes, ‘M1’ had the longest pollen tube 391.6 (μm), as well as the maximum pollen tube growth rate of 39 (μm h-1). The longest flowering periods were recorded to be 10 days in ‘M1’ and 7 days in ‘Mh1’, while the shortest period was 4 days in genotype ‘A5’ and ‘A3’. A significant correlation was found between pollen grain characteristics and initial fruit set, pistachio ounce, nut blanking, and as well malformed fruits. Based on the results pollens of genotype ‘M1’ decreased the nut blanking and malformed fruits in ‘Akbari’ cultivar, pollens of genotype ‘Mh1’ improved the pistachio ounce, and genotype ‘G1’ increased the initial fruit set.

The effect of pollen source on seed traits and dispersability in the heterocarpic annualCrepis sancta

AbstractAimsThe evolution and expression of dispersal-related traits are intertwined with those of other life-history functions and are manifested within various physiological constraints. Such a relationship is predicted between inbreeding levels and dispersability, which may be anatomically and ontogenetically linked so that the selection pressures on one may affect the other. While both the effect of inbreeding on reproductive success and on dispersal strategies received much attention, only a few studies considered both simultaneously. Furthermore, such studies often rely on two dichotomic representations of breeding and dispersal: using selfing versus outcrossing as a representation of breeding level, and dispersal ratio as the sole representation of dispersal strategy.MethodsHere, we used pollination experiments in the heterocarpic Crepis sancta (Asteraceae) to expand in two different manners on the common practice of using dichotomic representations of breeding and dispersal. First, we used pollination treatments that represent a continuum from selfing through pollination by kin to pollination by a distant neighbor. Second, we measured a whole set of continuous morphological and dispersal-related traits, in addition to measurements of reproductive success and dispersal ratio.Important FindingsThe proportion of developed capitula and the number of both dispersed and non-dispersed achenes were significantly lower in the self-pollination treatment in comparison to the outcrossed treatments. The effect of pollen sources on dispersal ratio was not statistically significant, though self-pollinated plants rarely produced non-dispersing seeds. Achene’s biomass increased with distance between parent plants, but pappus width did not, leading to a nonsignificant effect of pollination on falling velocity. Overall, pollen source affected mainly traits that were associated with reproductive output, but it had no clear effect on predominately dispersal-related traits. Such differences in the response of reproduction and dispersal traits to variation in pollen source suggest that dispersal-related selection is probably weak and/or masked by other forces.

Effect of pollen source on some fruit characteristics of exotic pear (Pyrus communis L.) cv. carmen and abate Fetel

A research experiment was conducted on two fruit bearing exotic cultivars “Carmen” and “Abate Fetel” of pear (Pyrus communis L.). The treatments included self, open and cross pollination of these two maternal parents with seven pollinizers viz., “William Bartlett”, “Fertility”, “Clapp’s Favourite”, “Chinese Sandy Pear”, “Max Red Bartlett”, “Kings Pear” and “Beurre de Amanalis”. The design of experiment was RCBD with three replications and the number of treatment combinations were 18. Pollen source affected the fruit colour significantly, wherein the highest value of red colour based on ‘a’ value was recorded with the pollen of “Max Red Bartlett” in the combination ‘Carmen × Max Red Bartlett’ (a=25.81) whereas, it was lowest with the pollen of “Kings Pear” (a=-16.63) in the combination ‘Abate Fetel × Kings Pear’, fruit shape, pedicle length and number of lenticles remain unaffected with the pollenizers used, however, sensory characteristics varied significantly with the pollenizers used.

Xenia studies in exotic and indigenous almond (Prunus amygdalus L.) varieties of Kashmir, India

Pollination is very important to obtain an economic yield, and the selection of pollinizer with suitable quality and quantity of pollen is an essential practice in different fruit plants. The effects of pollen parent on kernel and nut characters are known to occur in several nut crops and to determine the best pollinizer and effect of pollen source on the nut and kernel quality of almond (Prunus amygdalus L.). The present investigation was carried out at the experiment farm of Dryland Agriculture Research Station (DARS), SKUAST-Kashmir for two consecutive years, i.e. 2008 and 2009. Various cross combinations were made among nine almond (three exotic and six indigenous) varieties/selections which are compatible with each other. Their nut and kernel characteristics were determined and observed maximum nut weight (2.21 g), nut length (39.78 mm) and nut breadth (20.33 mm), kernel weight (1.28 g), kernel length (28.63 mm) and kernel breadth (12.61 mm) and shelling percentage (57.99 %). In the present study it has been observed that the parent with big nut and kernel size and weight influenced the nut and kernel size; nut and kernel weight of the recipient parent significantly (p?0.05).

Effect of physicochemical properties and phenolic compounds of bifloral propolis on antioxidant and antimicrobial capacity

In this study the effect of pollen source (mesquite and catclaw) on the sensory characteristics (appearance, color, aroma, taste, consistency and visible impurities), and physicochemical properties of raw propolis, and the phenolic content and biological activities of propolis extracts (PEs) was determined. The phenolic composition of PEs was determined by the total phenolic (TPC), flavone and flavonol (FFC), and flavanone and dihydroflavonol content (FDC). The individual phenolic components were analyzed by HPLC-DAD. The antioxidant activity was determined by the ferric-reducing power (FRAP) and free-radical scavenging activity (FRS). The antibacterial activity was evaluated against Gram-positive (Staphylococcus aureus and Listeria innocua) and Gram-negative (Echerichia coli and Salmonella thyphimurium) bacteria. The results showed that sensory characteristic and physicochemical properties of mesquite and catclaw propolis complied with international quality regulations. Fifteen phenolic compounds were identified, of which pinocembrin, naringenin, galangin, chrysin and quercetin were found a high concentration (> 3 mg/g). Mesquite propolis had the highest phenolic content (TFC and FDC), as well as antioxidant activity (> 2.5 mg Fe (II) equivalent/g; > 40% of DPPH radical inhibition) and antibacterial activity against Gram-positive bacterias in the order S. aureus > L. innocua (> 50% of inhibition for both bacterias at 500 µg/mL). These results indicating that pollen source affect the sensory characteristics and physicochemical properties of propolis, as well as the biological activity of their extracts.

Effect of Four Pollinating Sources on Nutritional Properties of Medjool Date (Phoenix dactylifera L.) Seeds

The objective of this study was to evaluate the effect of pollen source on the nutritional composition of seeds of the ‘Medjool’ date (Phoenix dactylifera L.) under conditions of northwest Mexico. The content of nutrients (protein, lipids, fiber, and ash), sugars (total, reducing, and non-reducing), and most abundant minerals, were evaluated, as well as antioxidant activities. The pollen of four cultivars (‘Deglet Noor’, ‘Khadrawy’, ‘Medjool’, and ‘Zahidi’) was selected. Four groups of three bunches were pollinated in each of the female palms. For the four treatments, the following ranges were obtained: Seeds had a weight of 1.32–1.41 g and low concentrations of protein (4.44–5.49 g/100 g) and lipids (9.62–10.19 g/100 g). The content of dietary fiber and ash was 59.65–72.59 g/100 g and 1.09–1.42 g/100 g, respectively. Total sugars content was 4.50–6.96 g/100 g, while the insoluble solids were 92.21–96.03 g/100 g. The predominant mineral was potassium with 399.97–459.79 mg/100 g dry weight, followed by sulfur with 135.51–162.67 mg/100 g dry weight. Finally, for antioxidant activities, DPPH (2,2′-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay results were 0.0014–0.0094 IC50 g/L and 0.176–0.299 IC50 g/L, respectively. The pollen sources had an effect on the physicochemical properties of the seeds of the ‘Medjool’ cultivar date. However, some of the parameters (diameter, total acidity, pH) did not show statistically significant differences. The pollen sources from the ‘Khadrawy’ and ‘Medjool’ cultivars were the ones that induced differences in physical, proximate, and nutritional parameters, while pollen from the ‘Zahidi’ source induced the largest differences for minerals. The results suggest that selection of the source of pollen has a significant effect on the nutritional properties of the date seed from the cultivar ‘Medjool’, and that its use could be feasible as a functional food or by-product of the date production.

Effect of pollen sources on yield oil extraction and fatty acid profile of the date seed (<em>Phoenix dactylifera</em> L.) cultivar Medjool from Mexico

The present investigation aimed to assess the effect of pollen sources on the mass, dimension, oil content and fatty acid profile of the seeds from female palms of the Medjool date cultivar. The palms were pollinated with Deglet Noor, Khadrawy, Medjool and Zahidi cultivars. In addition, three palms were pollinated as the treatment control. The fatty acids were evaluated by gas chromatography-mass spectrometry. The surface morphology of date seed powder was examined using SEM, before and after n-hexane interaction. The seeds of the Medjool treatment had the greatest mass (1.42 g), but the lowest oil content (5.37% w/w); the control seeds showed smaller mass (1.21 g), but higher oil content (13.57% w/w). The proportion of fatty acids varied significantly among the treatments with respect to the control. The most abundant fatty acids were oleic (C18:1), lauric (C12:0), myristic (C14:0), palmitic (C16:0), linoleic (C18:2), and stearic (C18:0). Together these fatty acids presented a composition between 98.3 and 98.67% for treatments, and 99.0% for the control. The results indicate that the pollen sources from Deglet Noor, Khadrawy, Medjool and Zahidi cultivars had a significant effect on mass, dimension, oil content and fatty acid profile of the seeds of the date cultivar Medjool. The date seed oil could be used as edible oil, in food products, and in pharmaceutical and cosmetic applications.

The strong effect of pollen source and pollination time on fruit set and the yield of tissue culture-derived date palm (Phoenix dactylifera L.) trees cv. Barhee

Generally, abnormal fruit set mostly in the form of setting parthenocarpic triple fruitlets is one of the most economically important disorders, which appears in trees of numerous TC (tissue culture)-derived date cultivars including cv. ‘Barhee'. To improve normal fruit set, fruit yield and fruit quality of such Barhee trees, effect of five pollen sources (three endogenous sources; ‘Beraim’, ‘Shahani’ and ‘Zahidi’ and two internationally recognized varieties; ‘Fard No. 4’ and ‘Jarvis No. 1’) at two pollination times (day of natural spathe cracking (DNC)11DNC; day of natural spathe cracking. and two days later (DNC+2)22DNC+2; two days after DNC.) was investigated on young TC-derived ‘Barhee’ trees. The study was conducted as split-plot in a randomized complete block design (RCBD), replicated three times, in hot, arid region of the southwest of Iran during the year 2013. The results indicated that the ‘Zahidi’ pollen had caused the highest percentage of normal fruit set (avg. 50.1%) and bunch yield (3.55kg) significantly (P≤0.05) superior than the other pollen sources, followed by Jarvis No. 1 (36.6%). The pollination with ‘Beraim’ pollen produced the lowest percentage of normal fruits (21.3%). The pollination at DNC was significantly (P≤0.05) higher in normal fruit set and bunch yield. The pollination with ‘Zahidi’ pollen at DNC brought the highest percentage of normal fruit set (57.5%) and maximum bunch yield (4.59kg) with acceptable fruit weight and size. Both mentioned factors and the interactive effect significantly (P≤0.05) influenced bunch ripeness. The pollen of ‘Jarvis No. 1’ at DNC yielded the highest percentage of bunch ripeness (96.91%). This pollen which had the second best normal fruit set and bunch yield was superior in showing off key metaxeic effects i.e. fruit volume, fruit weight, and pulp to seed ratio (w/w). The pollination at DNC significantly (P≤0.05) led to higher fruit length, diameter, volume and weight. Ultimately, we concluded ‘Zahidi’ pollen as the best choice for increasing normal fruit set and economical yield, ‘Jarvis No. 1’ pollen as the most suitable pollen source to benefit metaxenic effects and DNC as the best time for pollination of the TC-derived Barhee trees exhibiting abnormal fruit set and poor yield.

Pollen Source Influences Fruit Quality, Aril Properties, and Seed Characteristics in Pomegranate

ABSTRACTA study was conducted to determine the effect of pollen source on fruit, aril, and seed characteristics in pomegranate. The cultivar Malas Yazdi was pollinated with three pollen sources including: Rabab Neyriz (a commercial cultivar), Malas Pishva Varamin (selected superior local cultivar), and Poost Sefid Dezful (non-commercial cultivar). The results showed that the rate of fruit set from different pollen sources varied from 13% to 46%. Pollen source also had significant effects on other fruit properties, such as fruit weight, fruit shape, fruit length and diameter, fruit peel color, fruit peel thickness, and edible portion of the fruit. Aril characteristics including number of arils per fruit, aril length and diameter, aril weight, and aril color were also significantly affected by pollen source as well as seed physical properties, including seed weight, seed length and diameter, seed hardness, and seed toughness. However ‘Malas Pishva Varamin’ as a pollinizer showed the lowest rate of fruit set, but performed better in terms of fruit quality and seed characteristic than ‘Rabab Neyriz’ and ‘Poost Sefid Dezful’. This is the first observation of xenia effect in pomegranate breeding and could serve as a new area of research for pomegranate production. These findings suggest that selection of suitable pollinizer could be a new area of research for pomegranate production.

Effect of different pollination methods on physical and chemical characteristics of litchi (Litchi chinensisSonn.)

A field experiment was conducted to study the effect of pollen source in four litchi cultivars i. e. ‘Rose Scented’, ‘Calcuttia’, ‘Early Seedless’ and ‘Late Seedless’ as a result of self, cross and open pollination methods during two successive years 2013 and 2014. The two years’ pooled data showed that the cross pollination methods significantly improved the physical and chemical characteristics of fruit such as fruit weight (24.33 g) in Late Seedless × Early Seedless, fruit volume (23.75 ml) in Late Seedless × Early Seedless, total soluble solids (21.91°Brix)in Rose Scented × Early Seedless and minimum titratable acidity (0.45%) in Late Seedless × Rose Scented, while the maximum aril seed ratio (22.41) in Late Seedless × Late Seedless and titratable acidity (0.59%) in Calcuttia were estimated in self and open pollination methods, respectively, during both the years. The minimum fruit weight (18.39 g) in Calcuttia × Calcuttia, fruit volume (17.65 ml) in Calcuttia × Calcuttia and total soluble solids (18.40°Brix) in Early Seedless × Early Seedless were recorded in self pollination methods during both the years. The total sugar, reducing sugar and nonreducing sugar content did not differ significantly among the different pollination methods. Overall, increased fruit physical and chemical characteristics under the cross pollination suggest that the inclusion of cross-pollinators in litchi orchards may be beneficial for improving the fruit quality characteristics.

Effect of pollen source on hormones ABA and IBA, and Peroxidase and catalase Enzymes in seeds from Sh-12 cultivar (♀)☓Eskandar and Tuono (♁)

Abstract. This study was carried out during 2011 and 2012 in Horticultural Research Station of Seed and Plant Improvement Institute(SPII), Karaj, as factorial design base on randomized complete bloke design (RCBD) in triplicate with the aim to assess the effect of Effect of pollen source on hormones ABA and IBA, and Peroxidase and catalase Enzymes in seeds from Sh-12 cultivar (♀)Eskandar and Tuono (♁) in Steps before and after germination. The overall results of this study showed that the effect of pollen of Eskandar and Tuono on on hormons ABA and IBA, and Peroxidase and catalase Enzymes in seeds of Sh-12 cultivar was significant. Seed from the hybridizing of two Tuono and Sh-12 significantly has a higher amount of hormones ABA and IBA. The amount of the hormones ABA and IBA in seeds derived from this hybridizion is the average was5.66 and 2.14 micromol/gr while the amount of this hormone at levels seed from the hybridizing of Tuono and h-12on average 0.9 and 0.83 micromol/gr. The amount of enzyme activity of catalase significantly resulting in seed from the hybridizing of two Tuono and h-12 was higher in seed from the hybridizing of two Eskandar and Sh-12, but the mount of activity of this hormone had no significant differences with each other according to Peroxidase.

Pollen Source Effects on Fruit and Seed Traits of Jatropha curcas L.—A Renewable Biodiesel Feedstock

The effects of the pollen source on fruit and seed traits of Jatropha curcas and on potential biodiesel traits were investigated using analysis of breeding system and reciprocal pollination of various genotypes. The field experiments were carried out under Mediterranean conditions in Bet-Dagan, Israel. The breeding system was investigated by comparison of self-pollination with cross, open, and spontaneous self-pollination. Self-pollination, compared with cross-pollination, resulted in significantly lower levels of seed weight, oil concentration, oil content, and linoleic acid concentration in the seed-oil and with higher concentration of oleic acid. These seed traits were measured by near infrared reflectance spectroscopy (NIRS) as previously calibrated for J. curcas. Spontaneous self-pollination resulted in extremely low fruit and seed sets, and apomixis was totally absent. Pollen source effects were investigated by reciprocal pollination of selected genotypes; ‘Ethiopia,’ ‘Niger,’ and ‘Suriname’ both receiving and donating pollen. In addition, the genotype Brazil was used only as pollen source for the above mentioned genotypes. We found that most seed and oil traits were determined by the pollen recipient regardless of the type of pollen source. Additionally, when pollinated with Brazil, Ethiopia resulted in lower seed set, Niger resulted in higher content of seed protein and lower concentration of stearic acid in the seed oil, and Suriname resulted in higher concentration of linoleic acid and lower concentration of oleic acid. We suggest that enhancement of oil yield and oil quality in future plantations should be based either on a single elite genotype with nondetrimental self-pollination traits or on several elite genotypes with improved compatibility both as pollen sources and pollen recipients.

Effects of pollination limitation and seed predation on female reproductive success of a deceptive orchid.

For many species of conservation significance, multiple factors limit reproduction. This research examines the contributions of plant height, number of flowers, number of stems, pollen limitation and seed predation to female reproductive success in the deceit-pollinated orchid, Cypripedium candidum. The deceptive pollination strategy employed by many orchids often results in high levels of pollen limitation. While increased floral display size may attract pollinators, C. candidum's multiple, synchronously flowering stems could promote selfing and also increase attack by weevil seed predators. To understand the joint impacts of mutualists and antagonists, we examined pollen limitation, seed predation and the effects of pollen source over two flowering seasons (2009 and 2011) in Ohio. In 2009, 36 pairs of plants size-matched by flower number, receiving either supplemental hand or open pollination, were scored for fruit maturation, mass of seeds and seed predation. Pollen supplementation increased proportion of flowers maturing into fruit, with 87 % fruit set when hand pollinated compared with 46 % for naturally pollinated flowers. Inflorescence height had a strong effect, as taller inflorescences had higher initial fruit set, while shorter stems had higher predation. Seed predation was seen in 73 % of all fruits. A parallel 2011 experiment that included a self-pollination treatment and excluded seed predators found initial and final fruit set were higher in the self and outcross pollination treatments than in the open-pollinated treatment. However, seed mass was higher in both open pollinated and outcross pollination treatments compared with hand self-pollinated. We found greater female reproductive success for taller flowering stems that simultaneously benefited from increased pollination and reduced seed predation. These studies suggest that this species is under strong reinforcing selection to increase allocation to flowering stem height. Our results may help explain the factors limiting seed production in other Cypripedium and further emphasize the importance of management in orchid conservation.

The Effect of Pollen Source vs. Flower Type on Progeny Performance and Seed Predation under Contrasting Light Environments in a Cleistogamous Herb

Dimorphic cleistogamy is a specialized form of mixed mating system where a single plant produces both open, potentially outcrossed chasmogamous (CH) and closed, obligately self-pollinated cleistogamous (CL) flowers. Typically, CH flowers and seeds are bigger and energetically more costly than those of CL. Although the effects of inbreeding and floral dimorphism are critical to understanding the evolution and maintenance of cleistogamy, these effects have been repeatedly confounded. In an attempt to separate these effects, we compared the performance of progeny derived from the two floral morphs while controlling for the source of pollen. That is, flower type and pollen source effects were assessed by comparing the performance of progeny derived from selfed CH vs. CL and outcrossed CH vs. selfed CH flowers, respectively. The experiment was carried out with the herb Ruellia nudiflora under two contrasting light environments. Outcrossed progeny generally performed better than selfed progeny. However, inbreeding depression ranges from low (1%) to moderate (36%), with the greatest value detected under shaded conditions when cumulative fitness was used. Although flower type generally had less of an effect on progeny performance than pollen source did, the progeny derived from selfed CH flowers largely outperformed the progeny from CL flowers, but only under shaded conditions and when cumulative fitness was taken into account. On the other hand, the source of pollen and flower type influenced seed predation, with selfed CH progeny the most heavily attacked by predators. Therefore, the effects of pollen source and flower type are environment-dependant and seed predators may increase the genetic differences between progeny derived from CH and CL flowers. Inbreeding depression alone cannot account for the maintenance of a mixed mating system in R. nudiflora and other unidentified mechanisms must thus be involved.

Does provenance matter? Fitness is not determined by genetic distance or the scale of pollen dispersal inGrevillea sphacelata(Proteaceae)

Understanding how the scale of pollen transfer determines the outcome of matings is important evolutionarily and a key issue in restoration ecology. We tested the effects of pollen transfer distance for the self-incompatible shrub Grevillea sphacelata using (1) open pollination and transfer among (2) near neighbours, (3) neighbouring subpopulations and (4) populations separated by c. 4 km. We used AFLP markers to test for evidence of genetic differentiation within and among populations. Patterns of seed initiation suggest that open pollinated flowers were pollen limited, although in one subpopulation open seed set was greater than that achieved with pollen from near neighbours or other subpopulations. We detected no other effects of pollen source on seed initiation or seed and seedling development. In contrast, our genetic survey revealed significant spatial autocorrelation to 5 m, moderate differentiation of populations separated by up to 4 km and significant isolation by distance > 16 km. Our data suggest that, although dispersal of pollen may typically be localized, gene flow prevents localized adaptation or co-adaptation and we detected no effects of inbreeding depression. In a restoration context, our results imply that movement of seed between populations separated by 4 km will not have detrimental consequences, despite significant differentiation at neutral genetic markers, and may be beneficial in maintaining genetic diversity and evolutionary potential. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173, 290–302.