中国南亚热带和北温带地区禾本科C3与C4草本植物花果期差异研究

Studies on the Difference of Flowering and Fruity Period Between C3 and C4Herbaceous Plants of Poaceae in South Subtropical and North Temperate Climatic Zones of China

摘要:

为揭示不同地区禾本科C₃与C₄植物花果期受气候因子的影响，以广东省和内蒙古自治区分别代表南亚热带和北温带地区，从植物志中分别获得两地395和265种禾本科草本植物的3个花果期特征（始花期、末花果期和生殖期长），比较开花物候的差异，并通过一般线性模型探究其与气候因子（年均温与年均降水量）的相关性。结果表明，南亚热带与北温带地区C₃植物的始花期均比C₄植物早。两地C₄共有种在南亚热带地区具有更早的始花期、更晚的末花果期和更长的生殖期，而C₃共有种的末花果期在两地无显著差异，但在南亚热带地区始花期更早，生殖期更长。随年均温升高，北温带地区禾本科植物的始花期提前，而南亚热带地区则延后；随年均降水量升高，两地禾本科植物始花期与末花果期均延迟；禾本科植物生殖期长与年均温和年均降水量均不存在相关性。跨地区分析表明，末花果期、生殖期长与年均温和年均降水量均正相关，而与始花期不相关。禾本科C₃植物比C₄植物对地区间气候差异响应更敏感是两地共有种始花期差异显著的原因，而共有种生殖期长的显著差异则是由C₄植物末花果期结束较晚驱动的，其末花果期对地区间气候差异更敏感。这阐明了禾本科植物生殖物候差异的原因，以及禾本科植物花果期对不同气候区温度、降水的适应策略。

Abstract:

Reproductive phenology is a key indicator of plant individual reproduction and population succession. to reveal the influence of climate factors on the flowering and fruity period of C₃ and C₄ plants of Poaceae in different regions, Guangdong Province and Inner Mongolia Autonomous Region represent the south subtropical and north temperate climatic zones of China, and three reproductive phenological traits of 395 and 265 herbaceous species of Poaceae were obtained based on floras, respectively. The differences in initial flowering time, final flowering time and flowering duration between the two regions were compared, and the correlations between phenological traits and climatic variables (mean annual temperature and mean annual precipitation) were studied. The results showed that the start flowering stage of C₃ grasses in two regions was earlier than that of C₄ grasses. The C₄ common species of two zones had earlier initial flowering time, later final flowering time and longer reproductive period in south subtropical zone, while there was no significant difference in final flowering of C₃ common species, but the initial flowering stage was earlier and the reproductive period was longer in the south subtropical region. With the increase of annual temperature, the initial flowering time in north temperate region was advanced, but it was delayed in south subtropical region. With the increase of annual precipitation, the initial flowering time and final flowering time were delayed, and the reproductive period had no relation with neither mean annual temperature nor mean annual precipitation. The cross-regional analysis showed that the final flowering time and reproductive period were positively correlated with the mean annual temperature and annual precipitation, but did not the initial flower time. The significant difference in initial flowering time of common species was caused by higher sensitivity of C₃ grasses to climatic difference between two zones than C₄ grasses. The significant difference in reproductive period of common species was driven by the late end of final flowering time of C₄ grasses, which was more sensitive to regional climate differences. Therefore, it was clarified patterns and reasons of different reproductive phenology of Poaceae herbaceous species, and their adaptation strategies to temperature and precipitation across climatic zones.