澳洲坚果‘O.C’果实发育及品质变化规律研究

Fruit Development and Quality Change of‘O.C’Cultivar in Macadamia

为探究澳洲坚果果实生长和品质的变化规律,以6 a生‘O.C’为试材,于盛花期挑选状态基本一致的花序进行标记,跟踪测定果实横纵径、果形指数、单果质量、内果皮颜色、单壳果干质量、单果仁干质量、出籽率、出仁率、一级果仁率、粗脂肪、蛋白质、可溶性总糖及脂肪酸含量,对内果皮颜色及果实评价指标进行相关性分析,并采用主成分分析法对不同发育时期的果实品质进行综合评价。结果显示:(1)澳洲坚果果实横纵径、单果质量的生长趋势基本一致,呈“快速—缓慢—稳定”的“S”形曲线,果形指数呈近似“L”形。(2)花后105~195 d,内果皮颜色L^(*)值逐渐降低,a^(*)/b^(*)逐渐上升;壳果横纵径差异不显著;单壳果干质量、单果仁干质量、出仁率、一级果仁率、粗脂肪及蛋白质含量逐渐升高至稳定;出籽率、可溶性总糖含量呈下降—升高—稳定的变化趋势;不同发育时期的果仁中均检测出12种主要的脂肪酸,包括6种饱和脂肪酸、4种单不饱和脂肪酸和2种多不饱和脂肪酸。(3)相关性分析表明,39对性状呈极显著水平,16对性状呈显著水平,大多数品质指标间具有较强的相关性,且内果皮颜色与品质指标关系密切。(4)利用主成分分析法对果实品质进行综合评价,不同发育时期综合得分(Dn)的变化范围为-1.565~0.727,花后175 d的果实排名第一。结果表明,花后175 d为澳洲坚果‘O.C’的最佳采收时期,内果皮颜色的L^(*)值在35.73以下、a^(*)/b^(*)在1.48以上可作为该品种集中采收期确定的重要参考指标,研究结果为澳洲坚果‘O.C’丰产栽培及适时采收提供了理论依据。

In order to explore the changes in the growth and quality of Macadamia,6-year-old‘O.C’was used as the test material.Inflorescences that are basically in the same state are selected during the peak flowering period and marked,and the fruit transverse diameter,fruit longitudinal diameter,fruit shape index,Single fruit weight,endocarp color,dry weight of single shell fruit,dry weight of single kernel,fresh seed yield,kernel yield,first-class kernel rate,crude fat,protein,total soluble sugar and fatty acid content are tracked and measured.The correlation between endocarp color and fruit evaluation indices was analyzed,and principal component analysis was used to comprehensively evaluate the fruit quality at different developmental stages.The results show:(1)The growth trends of transverse diameter,longitudinal diameter and single fruit weight of Macadamia are basically the same,showing an"S"curve of"fast-slow-steady",and the fruit shape index is approximately"L".(2)From 105 to 195 days after full bloom,the L^(*)value of the endocarp color gradually decreased,and a^(*)/b^(*)gradually increased;There was no significant difference in the transverse diameter and longitudinal diameter of the shell fruit;The dry weight of single shell fruit,dry weight of single kernel,kernel yield,first-class kernel rate,crude fat and protein content gradually increased to a stable level;The frish seed yield and total soluble sugar content showed a trend of decrease-increase-stable;12 major species were detected in nuts at different development stages.Fatty acids,including 6 kinds of saturated fatty acids,4 kinds of monounsaturated fatty acids and 2 kinds of polyunsaturated fatty acids.(3)Correlation analysis showed that 39 pairs of traits showed extremely significant levels and 16 pairs of traits showed significant levels.Most quality indicators had strong correlations,and endocarp color was closely related to quality indicators.(4)The principal component analysis method was used to comprehensively evaluate fruit quality.The comprehensive score(Dn)at different development stages ranged from-1.565 to 0.727,and fruits 175 days after flowering ranked first.Research results show that 175 days after flowering is the optimal harvesting period of Macadamia‘O.C’.The L^(*)value of endocarp color is below 35.73 and a^(*)/b^(*)is above 1.48,which can be determined as the centralized harvesting period of this variety important reference indicators.The research results provide a theoretical basis for the high-yield cultivation and timely harvesting of Macadamia‘O.C’.