Mating pattern and pollen dispersal in an advanced generation seed orchard of Cunninghamia lanceolata (Lamb.) Hook.

Seed orchards represent the link between forest breeding and conifer production forests, and their mating patterns determine the genetic quality of seed orchard crops to a large extent. We genotyped the parental clones and their open pollination offspring in the third-generation seed orchard of Chinese fir using microsatellite markers and observed the synchronization of florescence in the seed orchard to understand the genetic diversity and mating structure of the seed orchard population. Genetic coancestry among parental clones was detected in the third generation seed orchard of Chinese fir, and the genetic diversity of the open-pollinated offspring was slightly higher than that of the parental clones. The external pollen contamination rate ranged from 10.1% to 33.7%, 80% of the offspring were produced by 44% of the parental clones in the orchard, and no evidence of selfing was found. We found that 68.1% of the effective pollination occurred within 50 m, and 19.9% of the effective pollination occurred in the nearest neighbors. We also found that successful mating requires about 30% of florescence overlap between males and females, and there was a significant positive correlation between male reproductive energy and male parental contribution. Our results provide a valuable reference for the management and design of advanced generation seed orchards.

Why bonobos show a high reproductive skew towards high-ranking males: analyses for association and mating patterns concerning female sexual states.

Among non-human primates, male dominance rank is not necessarily a good indicator of mating success, and relationships between male dominance rank and mating or reproductive success are affected by female behavior and sexual states implying their probability of conception. Although comparisons of the behavior of male chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) suggest that the effect of male dominance rank on mating success is expected to be less prominent in bonobos, recent genetic studies have shown that high-ranking male reproductive skew is higher in bonobos than in chimpanzees. One possible reason for the higher reproductive skew in bonobos could be that female behavior and their sexual states may have much more influence on male mating and reproductive success in bonobos than in chimpanzees. In the current study on bonobos, we conducted focal animal observation of females and analyzed the influence of female sexual swelling, the number of days after parturition, and dominance rank of males on female associations, and copulation with adult males. Our results showed that females with maximum swelling (MS) had more proximity with high-ranking males and copulated more frequently with higher-ranking males than with lower-ranking males. Females for whom longer time had elapsed since parturition, and therefore had higher probabilities of conception, had 5-m proximity with adult males more frequently than females whom shorter time had elapsed since parturition, but did not have more copulation with adult males. Females with MS had proximity and copulated with high-ranking males frequently, which partly explains why the reproductive skew is so high in bonobos. These results are discussed in relation to previous hypotheses on the influence of long-lasting mother-son relationships on mating success of males and on the contribution of female receptivity during non-conceptive nursing periods to moderate intermale aggression in bonobos.

Copulatory mechanism and functional morphology of genitalia and anal horn of the scorpionfly Cerapanorpa dubia (Mecoptera: Panorpidae).

The scorpionfly genus Cerapanorpa is characterized by the male possessing a single finger-like anal horn on the posterior portion of tergite VI. However, the functional morphology of this anal horn and the genitalia have not been studied to date. Herein, we investigated the functional morphology of the genitalia and the nongenital structures of the scorpionfly Cerapanorpa dubia by observing the mating process and dissecting the freeze-fixated pairs in copula to reveal the copulatory mechanism. The male C. dubia provides a solid salivary mass to the female as a nuptial gift prior to copulation. When the female starts to feed on the gift, the male uses his notal organ and complex genital structures to control the closest wing and genitalia of the female to establish a V-shaped mating position. In the maintenance phase of copulation, the male uses his anal horn in cooperation with the basally-constricted abdominal segment VII to clamp female abdominal segment VIII. The male hypovalves grasp female cerci, and move up and down rhythmically. The paired parameres clasp both sides of female tergite IX. The basal processes on male gonostyli grip the pleural membranes of the female genital chamber. In the sperm transfer phase, the male aedeagus directly couples with the female medigynium to transmit sperm by connecting his phallotreme to the female's copulatory pore. The evolution of the male complex grasping structures in Panorpidae is also briefly discussed.

Atypical assortative mating based on body size in an explosive-breeding toad from a tropical island of southern China.

Mating patterns exhibit considerable intra- and interspecific variation. Sexual selection can lead to the occurrence of random and assortative mating in different populations of the same species. Thus, understanding variation in mating decisions is crucial to understanding variation in the direction of sexual selection. We investigated natural mating patterns in Black-spectacled toads (Duttaphrynus melanostictus), an explosive-breeding species that breeds throughout the year. We captured amplectant pairs (137) and non-amplectant males (212) during breeding seasons from November 2016 to April 2017 in tropical-island population of southern China. Our study found no significant difference in snout-vent length (SVL) between amplectant and non-amplectant males. Female and male SVL were positively correlated with each other. Small females were paired more frequently with small males, less frequently with large males, but had no preference for or against medium males. Medium females exhibited no preference. Large females showed no preference for large males, but were paired less frequently with small males. These data suggested that successful amplectant males had body sizes representative of the entire population. Both random and size-assortative mating were present simultaneously in the same population and within the same breeding season. Female choice was important in shaping the mating behavior of Black-spectacled toads, promoting genotype-frequency stabilization and body-size diversity in the population.

Simultaneous spawning by female stream goby Rhinogobius sp. and the association with brood cannibalism by nesting males.

A laboratory experiment was conducted by varying the undersurface area of nesting substratum and the number of females in an experimental tank to elucidate the determinants of the mating pattern in the stream goby, Rhinogobius sp. cross-band type. Males with larger nests tended to attract two or more females to their nest in a tank. Moreover, males spawned simultaneously with multiple females and entire brood cannibalism by males was rarely observed under a female-biased sex ratio. When males spawned with a single female with low fecundity, however, entire brood cannibalism occurred at a high frequency, suggesting that a male guarding a nest with fewer eggs consumes the brood. Therefore, spawning behaviour of females that leads to a large egg mass would decrease the risk of entire brood cannibalism. In this species, simultaneous spawning by multiple females in a nest serves as a female counter-measure against entire brood cannibalism. These results suggest that a conflict of interest between the sexes through brood cannibalism is a major determinant of simultaneous spawning.

MATING PATTERN AND FITNESS-COMPONENT ANALYSIS ASSOCIATED WITH INVERSION POLYMORPHISM IN A NATURAL POPULATION OF DROSOPHILA BUZZATII.

Direct studies of mating success or mating pattern associated with Mendelian factors rarely have been carried out in nature. From the samples taken for the standard analyses of selection components, it is not usually possible to obtain the mating table, and only directional selection for male mating success can be detected. Both processes, mating pattern and differential mating probability, together with other fitness components, have been investigated for the inversion polymorphism of a natural population of the cactophilic species Drosophila buzzatii. Two independent samples of adult flies were collected: nonmating or single individuals (base population) and mating pairs (mating population). All individuals were karyotyped for the second and fourth chromosomes. A sequence of models with increasing simplicity was fitted to the data to test null hypotheses of no selection and random union of gametes and karyotypes. The main results were (1) no deviations from random mating were found; (2) differential mating probability was nonsignificant in both sexes; (3) inversion and karyotypic frequencies did not differ between sexes; and (4) karyotypic frequencies did not depart from Hardy-Weinberg expectations. These results are discussed in light of complementary evidence showing the need for interpreting with caution no-effect hypotheses such as the ones tested here. The use of complementary selective tests in these studies is suggested.

Patas monkey copulations: One mount, repeat if necessary.

Early, anecdotal reports of patas monkey (Erythrocebus patas) sexual behavior suggested that these primates were series-mount copulators. In 1975, limited evidence was presented in favor of single-mount copulations as the species-typical pattern for patas. The situation remained confused, however, as indicated by statements in a recent review article. This paper adds to our knowledge of patas sexuality by presenting quantitative data on the copulatory behavior of two additional adult males. Both males usually gave pelvic thrusts to intravaginal ejaculation once they had mounted a female and gained intromission. Mounts without ejaculation were clearly failed attempts at copulation, rather than segments of a stereotyped series-mount pattern. All of the available quantitative data indicate that the species-typical mating pattern for patas monkeys is copulation in a single mount.

Sociosexual behavior of a free-ranging Cebuella pygmaea (Callitrichidae, platyrrhini) troop during postpartum estrus of its reproductive female.

The sociosexual behavior of a free-ranging Cebuella pygmaea troop containing two adult males was studied throughout a postpartum periestrous period of its reproductive female. A clear-cut male-initiated six-day behavioral estrous period occurred from the 13th through 18th day postpartum, with a two-day peak of mating activity on the 15th and 16th days. Both adult males attempted to mate with the female, but the dominant male maintained exclusive mating access to her by guarding behavior and aggression toward the subordinate male. Estrus-related changes in the daily activity pattern included constant following of the female by the male, increased huddling and grooming between the consorts, a decrease in infant carrying, and suppression of insect foraging in the consorting male. Behaviors seen only during the periestrous period included genital presenting by the female, intensive licking and sniffing of her genitalia by the males, female-guarding by the dominant male, anogenital scent-marking on the male's body by the female, tongue protrusion and "tongue vibrating" by the male, and copulations, play chasing, and "consort walking" by the couple. Within the Callitrichidae, genital presenting and tongue vibrating in sexual context have been observed only in Cebuella.

Mating pattern variability among western toad (Bufo boreas) populations.

Breeding ecology and mating patterns of the western toad, Bufo boreas, were examined in three large explosively breeding populations in the Oregon Cascade Mountains. Two mating patterns occurred variably within and among the three populations. First, a large male mating advantage was observed in two of the three populations when data from all the days of data collection were combined. When each day of breeding was analyzed separately, there was a large male mating advantage on 3 of 5 days at one population, and mating was random on all days at the two other populations. The second mating pattern, positive assortative mating by size, was observed at two of the three populations. This pattern was found on separate days of breeding as well as when data from all days were combined at one population, and on only one day of breeding at the second population.In a survey of anuran amphibian mating patterns, intraspecific variation was found in 13 of 15 species, including the present study of the western toad. Intrapopulation variation in mating patterns among breeding years has been observed in 5 of 8 anurans, whereas within-site, within-year mating pattern variation has only been reported for the western toad. These results strongly suggest that anuran mating patterns are frequently neither species-specific nor population-specific attributes. Variable mating patterns were most commonly observed in explosively-breeding anurans. Explosive breeders may be susceptible to variable mating patterns because they may be more sensitive to fluctuations in environmental conditions, demographic parameters, and the intensities of intrasexual competition and mate choice.