不同产地花楸无性系苗期田间耐热性评价研究

【目的】花楸是分布在我国山区海拔500~2200 m的重要乡土树种,具有极高的观赏价值。本研究对不同花楸无性系的田间耐热性进行综合评价,为早期筛选出适应于北京高平原地区的优良品种提供科学依据。【方法】以来自5个种源的14个无性系花楸的2年生嫁接苗为材料,在北京延庆海拔500 m的田间条件下,对幼苗的苗高和地径的生长量、叶片丙二醛(MDA)、可溶性蛋白、可溶性糖和叶绿素含量以及SOD、POD的活性进行测定;利用基于主成分分析的隶属函数分析法对14个无性系花楸幼苗的耐热性进行了综合评价。【结果】各单项指标值在4个月之间的差异显著,且在不同无性系之间的差异也显著;WL1、WL2、SH1和SH2的苗高和地径的生长表现显著优于其他无性系。TB1和TB2的生长表现最差;TB1和TB2的MDA含量从5月到6月升高最显著,耐热性表现差。FN2和WL2的MDA含量从5月到6月反而下降,优于其他无性系;WL2、FN1和FN2的两种保护酶活性高,优于其他无性系;FN1和FN2的叶绿素含量受高温的影响下降最少,优于其他无性系;SS1、SS2、SS3和SS4的渗透调节物质含量较高,优于其他无性系。指标的相关性分析表明,叶绿素含量两两间呈显著正相关关系(P<0.01);叶绿素含量变化与地径增长量间呈显著负相关关系(P<0.05);苗高和地径之间呈显著正相关关系。10个单项指标经过主成分分析后,得到4个新的相互独立的综合指标;【结论】经过隶属函数综合评价,各无性系幼苗的田间耐热性从强到弱的顺序为:WL2、WL1、FN1、SH2、SH1、FN2、SS2、HS2、SS4、SS3、SS1、HS1、TB2、TB1。

Evaluation on field heat resistance of Sorbus pohuashanensis clonal seedlings introduced from different regions

ObjectiveSorbus pohuashanensis is one of the important Chinese native tree species with high ornamental value ranging from 500 to 2 000 m altitude. In this study, the field trial for heat resistance of different clones was evaluated comprehensively, which provided scientific basis for early selecting fine varieties adapting to high plains in Beijing.Method2-year-old grafted seedlings of 14 clones from 5 provenances were used as materials. In the field trial, which performed in Yanqing County of Beijing with 500 m altitude, the height and stem growth of seedlings, content of malondialdehyde (MDA), soluble protein, soluble sugar, chlorophyll in the leaves, activity of superoxide dismutase (SOD) and peroxidase (POD) in the leaves were measured; and the heat resistance of 14 clones was evaluated comprehensively by membership function analysis based on principal component analysis.ResultThe value of each single index showed significant difference among 4 months and was significantly different among different clones. The growth performance of Wuling1 (WL1),Wuling2 (WL2), Shihui1 (SH1) and Shihui2 (SH2) was significantly better than other clones. The growth performance of Taibai1 (TB1) and Taibai2 (TB2) was the worst; the MDA contents of TB1 and TB2 increased most significantly from May to June, showing poor heat resistance. However, the MDA contents of Fengning2 (FN2) and WL2 decreased, showing stronger heat resistance than other clones. The activity of two protective enzymes of WL2, Fengning1 (FN1) and FN2 was higher than other clones. The chlorophyll content of FN1 and FN2 was minimally impacted by high temperature; the content of osmotic regulator of Songshan1 (SS1), Songshan2 (SS2), Songshan3 (SS3) and Songshan4 (SS4) was higher than other clones. Correlation analysis showed significantly positive correlation between every two groups of chlorophyll content (P < 0.01); chlorophyll and ground diameter growth (P < 0.05) were significantly negatively correlated. Significantly positive correlation was found between seedling height and ground diameter of seedlings; after principal component analysis, 10 single indexes were transformed into 4 new independent comprehensive indexes;ConclusionAfter the comprehensive evaluation of membership function, the sequence of field heat resistance of each clone seedling from strong to weak is: WL2, WL1, FN1, SH2, SH1, FN2, SS2, Huangshan shuiyu2 (HS2), SS4, SS3, SS1, Huangshan shuiyu1 (HS1), TB2, TB1.