关键词: 红花油茶, 种质资源, 变异分析, 主成分分析, 综合评价

Abstract:

Objective: To protect and develop the Camellia phellocapsa, a systematic survey of C. phellocapsa was conducted, followed by grafting and preservation. The unique germplasm resources with high oil yield and ornamental value were explored. This study aims to provide crucial resources for the development and utilization of C. phellocapsa and the breeding of new varieties. Method: A systematic survey and evaluation were conducted on 268 mature C. phellocapsa in Chaling County, focusing on morphological characteristics, flowering period, fruit economic traits, dry seed oil content, and fatty acid composition. Through comparing the data collected in two consecutive years, the principal component analysis and membership function analysis were used to comprehensively evaluate the most outstanding individual trees. Twelve high-yielding, distinct new germplasm lines were preliminarily identified primarily based on fruit yield per tree, fruit morphological distinctiveness, flower quantity, and color, and designated as follows: A-88, A-102, D-21, D-22, D-47, F-2, A-52, A-109, A-127, D-13, D-36, and D-50. Result: In terms of individual fruit weight and fruit yield per plant, A-88 performed exceptionally well, with an average individual fruit weight of 131.57 g, which was 115.58% higher than that of A-127, a statistically significant difference (P<0.05). D-47 had the highest fruit yield per plant, producing 65 fruits per plant with a total weight of 8.85 kg. In terms of fruit morphology, A-52 had the largest fruit diameter (89.93 mm), which was 65.43% greater than that of D-50. A-102 exhibited the best fruit length (96 mm), which was 71.18% greater than the shortest fruit length of A-109. Comparison revealed that although A-52 had the largest fruit diameter, its individual fruit weight was significantly lower than that of A-88 (P<0.05), indicating that factors such as fruit shape and skin thickness also influence individual fruit weight. Regarding oil characteristics, A-88 had the highest oil content in dry seeds and unsaturated fatty acid content, at 42.13% and 86.43%, respectively, and the oil content in dry seeds was 20.54% higher than that of D-47, a significant difference (P<0.05), and its unsaturated fatty acid content was 3.22% higher than that of A-127, which had the lowest value. F-2 had the highest oleic acid content at 82.14%, which was 12.66% higher than the lowest value in A-127, and the difference was significant (P<0.05). In summary, A-88 has both high oil content and high unsaturated fatty acids, while F-2 stands out for its high oleic acid content. Both exhibit significant potential for development in edible and cosmetic oils. Regarding floral phenotypes, F-2 exhibited outstanding ornamental traits. Its flowers displayed a vivid rose red color (RHS 58A), with a maximum of 402 blooms per plant and a prolonged peak flowering period of 42 days, demonstrating outstanding ornamental qualities. D-21 and D-47 exhibited peach-pink flowers (RHS N57A) with abundant blooms, also possessing considerable ornamental value. Comprehensively, F-2 exhibits outstanding traits in flower color, flower quantity, flowering period, and flower size, demonstrating high potential for both ornamental use and breeding. Correlation analysis revealed that there were 4 pairs of traits with extremely significant correlations and 8 pairs with significant correlations among 28 traits. Principal component analysis indicated that the cumulative contribution rate of the first 4 principal components reached 82.75%. Through the membership function method, a comprehensive evaluation was conducted on 12 germplasm samples, and ultimately six C. phellocapsa with outstanding phenotypic traits were successfully selected. Conclusion: The results indicate that six C. phellocapsa germplasm with excellent phenotypic traits have been screened, namely A-88, A-102, D-22, D-21, D-47, F-2, providing important reference for the evaluation of C. phellocapsa germplasm resources and the selection of superior varieties.

Key words: Camellia phellocapsa, germplasm resources, analysis of variance, principal component analysis, comprehensive evaluation