Genetic Diversity of Volatile Components in Xinjiang Wild Apple (Malus sieversii)

新疆野苹果挥发性化合物组分的遗传多样性研究(英文)

To evaluate genetic relationships using qualitative and/or quantitative differentiation of volatile components in Xinjiang Wild Apple （Malus sieversii （Lebed.） Roem.） and to acquire basic data for the conservation and utilization of the species, aroma components in ripe fruit of M. sieversii obtained from 30 seedlings at Mohe, Gongliu County, Xinjiang Autonomic Region, China, and in ripe fruit of 4 M. purnila cultivars （＇Rails＇, ＇Delicious＇, ＇Golden Delicious＇, and ＇Fuji＇） were analyzed using head space-solid phase microextraction and gas chromatography-mass spectrometry. The results indicated that the values of similarity coefficient concerning volatile types between the two species were in accordance with the evolution of M. pumila cultivars （forms）, and that M. sieversii seedlings showed considerable genetic variations in these aspects： the total content of volatile components, the classes and contents of each compound classes, the segregation ratio, and content of main components. The results showed significant difference among seedlings and wide genetic diversity within the populations. Comparison of the volatile components in M. sieversii with those in M. pumila cultivars showed that the common compounds whose number were larger than five with the contents over 0.04 mg/L simultaneously between M. sieversii and M. pumila cultivars belonged to esters, alcohols, aldehydes or ketones. This suggests fundamental identity in main volatile components of M. sieversii and M. pumila cultivars. The results above sustained the conclusion ＂M. sieversii is probably the ancestor ofM. purnila＂. However, there were 48 compounds present in M. puraila that were not detected in M. sieversii, including 6 character impact components （i.e., propyl acetate, （Z）-3-hexenal, 2-methyl-l-butanol acetate, pentyl acetate, 3-furanmethanol, and benzene acetaldehyde）. This suggested that in the domestication of M. pumila, introgression of other apple species, except for M. sieversii, by interspecies hybridization was possible. There were 177 compounds in total belonging to 11 classes detected in 30 M. sieversii seedlings, including esters, alcohols, ketones, aldehydes, acids, benzene ramifications, terpenes, heterocycles, hydrocarbon derivates, acetals, and lactones. Among them, acetals and lactones were not detected in M. pumila cultivars, 90 compounds were unique to M. sieversii, and 7 components （l-butanol, ethyl hutanoate, 1-hexanol, ethyl hexanoate, 3-octen-1-ol, ethyl octanoate, and damascenone） belonged to character impact odors. Thus, the potential of M. sieversii in ＂utilization conservation＂ is enormous as a rate germplasm on genetic improvement of M. pumila cultivars.

以中国新疆伊犁地区巩留县莫合镇的新疆野苹果(Malussieversii(Lebed.)Roem.)30个实生株系及国光、元帅、富士、金冠等苹果(MaluspumilaMill.)品种的成熟果实为试材,采用顶空固相微萃取和气相色谱质谱联用技术,分析香气成分,旨在为探讨新疆野苹果与栽培苹果的亲缘关系及为新疆野苹果资源保护利用提供基本资料。结果表明,①根据新疆野苹果与栽培苹果共有挥发性化合物种类数计算相似系数,其大小与苹果品种(类型)的演化历史相吻合;②新疆野苹果各实生株系挥发性化合物总含量、各类挥发性化合物种类数及其含量以及主要挥发性化合物分离比率与含量等存在广泛的遗传变异,参试的30个实生株系间差异明显,遗传多样性极为丰富;进一步与4个栽培苹果品种挥发性化合物组分进行比较,结果发现,新疆野苹果与栽培苹果品种化合物种类数在5以上、含量在0.04mg/L的化合物均属于酯类、醇类、醛类和酮类,说明新疆野苹果与栽培苹果的主要挥发性化合物组分基本一致,上述研究结果支持“新疆野苹果可能是栽培苹果的祖先种”的结论,但有48种成分为栽培苹果特有的挥发性化合物成分,在新疆野苹果检测不到,其中乙酸丙酯及苯乙醛等6种成分为特征香气成分。因此,栽培苹果可能是杂种起源;③从新疆野苹果30个实生株系中共检测到包括酯类、醇类、酮类、醛类、酸类、苯衍生物、杂环类、萜类、烃类、缩醛类和内酯类等11类化合物177种,其中缩醛类和内酯类化合物在栽培苹果品种中没有检测到,90种成分为新疆野苹果特有成分,1-丁醇及大马酮等7种成分为香气值大于1的特征香气成分。因此,新疆野苹果作为栽培苹果遗传改良的珍贵资源,进行“利用保存”的潜力很大。