Change Of Leaf Morphological Traits And Fluctuating Asymmetry In Plants Along Altitude Gradient Of Meli Snow Mountain

Leaf traits affect the growth,survival and adaptation of plant, including acquisition, use, storage of resources and adaptability to the environment, among which leaf morphological traits reflect the surviving strategies of plants adapting to environmental changes. Leaf fluctuating asymmetry represents small, random variation from symmetry and has been suggested as a useful indicator of environmental stress.In the study, we focused on the relationship of altitude, leaf morphological traits and leaf fluctuating asymmetry. Leaves from six broadleaved plants were collected and ten leaf morphological traits were measured by software Lamina, including leaf area, specific leaf area, leaf dry matter, leaf perimeter, square perimeter/area, circularity, leaf length/leaf width, number of indents, mean of indent depth and width. Eight fluctuating asymmetry (FA) index were also measured by software E-ruler, including FAh1, FAh2, FAh3, FAv4, FAt1, FAt2, FAT3and FAT4. The change of leaf morphological traits and fluctuating asymmetry along altitudinal gradient and their correlations were analyzed using R. The results were summarized as follows:1. Change of leaf morphological traits along altitude:(1) With the increase of altitude, leaf area, lead dry matter, specific leaf area, leaf perimeter and number of indent decreased;(2) With the increase of altitude, compactness, circularity, length/width, mean of indent width and mean of indent depth showed various pattern without clear tendency;(3) Different leaf morphological index has significant correlation with each other.2. Leaf fluctuating asymmetry increased consistently with the increase of altitude and it appeared to be a reliable indicator of stress caused by altitude increase. However, the six species have different strategies in response to altitude increase. The most sensitive index was FAv1which measured the fluctuating asymmetry in vertical, FAh1(horizontal25%), FAH1(horizontal50%) and FAH3(horizontal75%) followed. We also find significant correlation between different leaf fluctuating asymmetry index.