Responses of Leaf Functional Traits of Torreya fargesii to the Altitudinal Variation

[Objective] To reveal the leaf functional traits and adaptive strategy of Torreya fargesii at different altitude gradients.[Method] Leaves of T. fargesii were selected from the altitudes of 1 570, 1 700, 1 900, 2 125 and 2 360 m in Jiajinshan forest area of Sichuan Baoxing County, and the altitudes of 1 000, 1 200, 1 450, and 1 700 m in Hua'eshan Mountain Nature Reserve of Sichuan Wanyuan County as the research materials. Leaf blade traits such as leaf length, leaf width, leaf girth, leaf area and leaf dry weight were determined, and the influence of altitude on each index and correlation between characters were analyzed. [Result] For the leaves from both Baoxing County and Wanyuan County, leaf length, leaf width, leaf girth, leaf aspect ratio and leaf area decreased with the increase of altitude. There was no significant difference in the changes of leaf width, leaf girth and leaf aspect ratio among different altitudes(P>0.05), while the difference was significant in leaf length between high altitude and low attitude(P<0.05), and the difference was also significant in leaf area for the leaves from Baoxing County between high altitude and low altitude. However, there was no obvious correlation between leaf width and altitude, which could be considered as a relatively stable parameter. Leaf thickness and leaf dry weight increased first and then decreased with altitude,while the specific leaf area decreased first and then increased. In leaf length, leaf girth, leaf width and leaf area parameters, except for leaf width and leaf area for the T. fargesii from Wanyuan County, any two parameters reached significant or very significant positive correlation level(P<0.01). Leaf dry weight and leaf thickness had significant or very significant positive correlation, leaf dry weight and leaf area had a certain positive correlation but not significant. There existed no significant positive correlation between specific leaf area and leaf area, while specific leaf area was in negative correlation with leaf dry weight, and the negative correlation of specific leaf area with leaf area of T. fargesii from Wanyuan County reached the significant level.[Conclusion] T. fargesii adapted to different altitudes by changing leaf dry weight, leaf area and leaf area ratio, and the most suitable altitudes for the growth of T. fargesii were 1 900 and 1 450 m in Baoxing and Wanyuan area respectively.

Effects of fruit bagging on the physiochemical changes of grapefruit(Citrus paradisi)

Fruit bagging is a commonly used cultivation measure to protect citrus fruit from insects and adverse environments.The present study aimed to comprehensively investigate the effects of bagging on the physiochemical characteristics of grapefruit.The grapefruit were bagged at approximately 110–120 d after anthesis with a one-layer kraft paper bag with black coating inside(SL),a double-layer kraft paper bag with one black paper as the inner layer(DL),and a three-layer kraft paper bag with two black papers as inner layers(TL),respectively.Ultra performance liquid chromatography-high resolution mass spectrometry(UPLC-HRMS)technique was used to identify a total of 19 flavonoids,2 phenylpropanoids,9 coumarins,and 5 limonoids.By using UPLC,50 carotenoids were identified.Gas chromatography–mass spectrometry was used to identify 3 soluble sugars,3 organic acids,and 11 amino acids.In the quantitated components in the peel(albedo and flavedo),the chlorophylls and the carotenoids components(such as luteoxanthin,violaxanthin,9-cis-violaxanthin,xanthophyll,zeaxanthin andβ-carotene)were significantly downregulated by bagging,causing the surface color of bagged fruit to turn yellow earlier but paler than that of the unbagged control,particularly in the three-layer kraft bag treatment.Unlike the peel,the color and the carotenoid content of the juice sacs were less affected.The physiochem-ical compounds other than pigments,including soluble sugars,organic acids,amino acids,flavonoids,coumarins and limonoids,were minimally affected by bagging treatments.Our results indicated that bagging at approximately 110–120 d after anthesis exerted influence mainly on peel color,but less on sugars,acids,amino acids,flavonoids,limonoids and coumarins of grapefruit.