新疆野杏开花物候与花器官对海拔的响应

The flowering phenological period and floral organ response to altitude in Prunus armeniaca

新疆野杏(Prunus armeniaca Lam.)是天山野果林的优势种,具有重要的生态与资源价值。野果林的生境条件与其分布及生长密切相关。为了明确新疆野杏在不同海拔下的开花物候与花器官变化规律,于2021年3月—4月,选择新疆新源县吐尔根杏花沟野杏林为研究区,在野杏集中分布的1000—1500m的山地,由低到高划分Ⅰ—Ⅴ级海拔梯度设置样地,监测环境条件,对野杏群体开花物候期与花器官发育特征进行调查。结果表明:(1)新疆野杏群体开花物候期历时32d左右,各海拔梯度最长相差2d,第Ⅰ级与第Ⅱ级海拔的开花物候期差异不明显,其他海拔梯度间均存在显著差异,开花最晚的第Ⅴ级比最早的第Ⅰ级晚9d,但群体开花期长4d,海拔梯度与开花物候期呈显著正相关,而温度与开花物候期呈显著负相关;(2)新疆野杏的花萼长度和宽度、子房高度和宽度均是第Ⅱ级海拔的最大;花冠直径、花瓣纵径和横径均是第Ⅰ级的最大,花药长度和宽度均是第Ⅳ级的最大;花柱长度是第Ⅴ级的最大。海拔与花的外部器官、雌蕊呈显著负相关,与雄蕊呈显著正相关;光照强度与花的外部器官、雌蕊呈显著负相关;(3)新疆野杏开花期气候因子,第Ⅳ级、第Ⅴ级与第Ⅰ级存在显著差异,海拔梯度与湿度、光照强度呈显著正相关,与温度呈显著负相关。新疆野杏群体开花物候期历时约32d,随海拔升高,野杏林地光照强度增强,温度降低,湿度增大;野杏开花物候期推迟,开花期历时增长,每升高100m,开花期推迟约1.8d;野杏花雄蕊发育逐渐增大,雌蕊和花的外部器官发育逐渐减小,是新疆野杏对海拔变化的适应性。研究结果可以为野杏种群分布适应性研究提供理论依据。

Prunus armeniaca Lam.is the dominant species in the wild fruit forest in the Tianshan Mountains and has important values of ecology and resource.The altitude of wild fruit forest is closely linked to its distribution and growth.To clarify the changes of flowering phenological period and floral organs of P.armeniaca in different altitudes,the P.armeniaca forest in Tuergenxinghuagou,Xinyuan County,Xinjiang was selected as the research region from March to April 2021.In the mountainous area of 1000—1500 m with concentrated distribution of P.armeniaca,the sample plots were set up at the altitude gradient of I—V grade from low to high.We monitored the environmental conditions,and investigated the flowering phenological period and floral organ development characteristics of P.armeniaca population.The results showed that:(1)the flowering phenological period of P.armeniaca population lasted about 32 d,and the longest difference of each altitude gradient was 2 d.There was no significant difference in flowering phenological period between the grade I and gradeⅡ,and there were significant differences between other altitude gradients.The last flowering grade V was 9 d later than the earliest flowering grade I,but the flowering phenological period of the P.armeniaca population was 4 d.The altitude was significantly positively correlated with the flowering phenological period,while temperature was significantly negatively correlated with flowering phenological period;(2)The sepalled length and width,ovary height and width of P.armeniaca were the largest at grade II;corolla diameter,petal longitudinal diameter and transverse diameter were the largest in grade I,while the anther length and width were the largest in grade IV;the style length was the largest in grade V.Altitude was significantly negatively correlated with the external organs and pistils of flowers,and positively correlated with the stamens.Light intensity was significantly negatively correlated with the external organs and pistils of flowers;(3)Climatic factors for the flowering period of P.armeniaca,with significant differences between grade IV,grade V and grade I.Altitude gradient and humidity,light intensity showed significantly positive correlation,altitude gradient and temperature showed significantly negative correlation.The flowering phenological period of P.armeniaca population in Xinjiang lasted about 32 d.As altitude rises,light intensity increases,temperature decreases and humidity increases in P.armeniaca woodlands.The flowering phenological period of P.armeniaca was delayed,and the flowering period increases in duration,with each 100m rise delaying flowering by about 1.8 d;the development of stamens gradually increased,and the development of external organs of pistils and flowers gradually decreased,which was the adaptability of P.armeniaca to altitude changes.The results can provide a theoretical basis for the study on the adaptability of P.armeniaca population distribution.