Plant sexual systems correlated with morphological traits: Reflecting reproductive strategies of alpine plants

Abstract

Plant sexual systems can be affected by various environmental factors, and thus show a range of morphological differences. The associations between plant sexual systems and morphology are unique, for example, the subnival belt of the Hengduan Mountains has harsh climatic conditions, but hosts remarkable biodiversity. However, these associations have received surprisingly little attention. We analyzed the associations in this region, and compared the pattern of sexual systems with that of other floras, and we also reviewed the breeding system of 36 alpine species. Information on plant sexual systems and these traits were mainly based on published information, herbarium collections, and field observations. The results showed that there was a high proportion of hermaphroditic species and a low proportion of dioecious and monoecious species. Hermaphroditism was strongly associated with showy floral displays, specialist entomophily, and perennial forbs. Dioecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, and shrubs, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, and perennial grasses. Although no association was found between sexual systems and fruit type, plants with dry fruits (98.1%) were predominant in our study region. With respect to the plant breeding systems in the alpine region of southwest China, we predicted that pollination service might be particularly low; most of the plants lacked enough outcrossing pollinators. Our data revealed that 97.1% of the hermaphroditic species were self-compatible, and 88.2% of them showed autonomous or facilitated selfing. The plant sexual systems identified might serve to optimize the probability of pollination and thus ensure reproductive success.

Alien plant species that invade high elevations are generalists: support for the directional ecological filtering hypothesis

“…Since low stature is a common adaptation in alpine species (Billings ; Fabbro & Körner ; Peng et al. ), lower plant height of alien species occurring at higher elevations is in line with the predictions of the ALH.…”

Drivers of large‐scale geographical variation in sexual systems of woody plants

“…Solar radiation may affect the relative representation of sexual systems via its influence on flower coloration (Peng et al, 2014). For example, Peng et al (2014) found that hermaphroditism was significantly associated with showy flower colour in alpine plants. Quantifying the influence of solar radiation on the frequency of different sexual systems via flower coloration deserves further study.…”

Evolutionary history and underlying adaptation of alpine plants on the Qinghai–Tibet Plateau

“…In both annuals and perennials, autonomous selfing was found to have provided reproductive assurance under pollinator scarcity (e.g., Zhang & Li, ; Duan et al, ), even under strong inbreeding depression (Zhang et al, , ). In the subnival region of the SE QTP, more than 85% of the total number of species are hermaphroditic, likely favoring selfing when pollinators are unavailable (Peng et al, ).…”