不同耐旱型马尾松家系幼苗针叶挥发物组分对干旱胁迫的响应

Response of volatile components in needles of different drought tolerant families of Pinus massoniana seedlings to drought stress

关键词:  马尾松  干旱胁迫  挥发物  组分  相对含量

Key words:  Pinus massoniana, drought stress, volatiles, component, relative content

摘要:

为探明抗旱型和干旱敏感型马尾松家系幼苗在干旱胁迫下针叶挥发物的变化特征，该研究采用固相微萃取-气相色谱-质谱联用技术，分别对抗旱型和干旱敏感型马尾松幼苗不同阶段（正常培育、轻度干旱、重度干旱、干旱复水）的针叶挥发物组分和相对含量进行测定。结果表明：（1）检测和鉴定出马尾松幼苗松针挥发物组分16种，其中单萜组分5种（α-蒎烯、β-蒎烯、月桂烯、柠檬烯、异松油烯），倍半萜组分9种（γ-榄香烯、胡椒烯、β-榄香烯、长叶烯、石竹烯、葎草烯、α-摩勒烯、γ-摩勒烯、δ-杜松烯），酯类组分2种（甲酸芳樟酯、乙酸龙脑酯）。（2）不同类型马尾松针叶挥发物组成基本相同，且主要由单萜和倍半萜组成，相对含量较高的化合物有α-蒎烯、β-蒎烯、石竹烯等，主要化合物（相对含量＞1%）的相对含量差异不显著。（3）在轻度干旱胁迫下，敏感型家系针叶挥发物中单萜组分的相对含量急剧下降，其中α-蒎烯和β-蒎烯的相对含量由未经干旱胁迫状态下的39.671%和14.383%分别下降至16.855%和5.048%。抗旱型家系在干旱胁迫下针叶挥发物中单萜相对含量有所降低（下降幅度远小于敏感型家系），且在干旱复水后单萜组分相对含量上升，有恢复至未经干旱胁迫状态下的趋势。（4）抗旱型马尾松幼苗在干旱胁迫时松针挥发物组分相对含量变化小，干旱敏感型马尾松幼苗在干旱初期针叶挥发物组分急剧变化以适应外部胁迫。针叶中单萜组分（α-蒎烯、β-蒎烯）在干旱胁迫下的响应程度是敏感型和抗旱型家系最显著的差别。该研究为马尾松针叶挥发物响应干旱胁迫机理研究奠定了基础，为马尾松抗旱育种提供了思路。

Abstract:

To investigate the variation characteristics of needle volatile compounds in seedlings from drought-resistant and drought-sensitive?Pinus massoniana?families under drought stress, this study used solid-phase microextraction-gas chromatography-mass spectrometry to determine the components and relative contents of needle volatiles in drought-resistant and drought-sensitive Pinus massoniana seedlings at different stages (normal cultivation, mild drought, severe drought, and drought rewatering). The results were as follows: (1) Sixteen kinds of volatile components from pine needles of Pinus massoniana seedlings were detected and identified, including five monoterpenes (α-pinene, β-pinene, myrcene, limonene, and terpinolene), nine sesquiterpenes (γ-elemene, copaene, β-elemene, longipinene, caryophyllene, humulene, α-muurolene, γ-muurolene, and δ-cadinene) and two esters (linalyl formate and bornyl acetate). (2) The components of needle volatiles in seedlings of drought sensitive and drought resistant Pinus massoniana families were basically the same, mainly composed of monoterpenes and sesquiterpenes. The compounds with relatively high relative contents include α-pinene, β-pinene, caryophyllene, etc., and there is no significant difference in the relative contents of the main components (relative content greater than 1%). (3) Under mild drought stress, the relative content of monoterpene components in needle volatiles of sensitive families decreased sharply, and the relative contents of α-pinene and β-pinene decreased from 39.671% and 14.383% in the unstressed state to 16.855% and 5.048%, respectively. Under drought stress, the relative content of monoterpenes in needles of drought resistant families decreased (the decline range was much smaller than that of sensitive families), and the relative content of monoterpenes increased after drought rehydration, tending to return to the state without drought stress. (4) The relative content of volatile components in pine needles of drought resistant Pinus massoniana seedlings changed little under drought stress, while those of volatile components of pine needles of drought sensitive Pinus massoniana seedlings changed sharply in the early stage of drought to adapt to external stress. The response of monoterpene components (α-pinene and β-pinene) in needles to drought stress was the most significant difference between sensitive and resistant families. This study laid a foundation for the study of the mechanism of Pinus massoniana needle volatiles in response to drought stress, and provided ideas for Pinus massoniana drought resistance breeding.