辐射分化

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马铃薯“身世之谜”如何被解开?
Huan Qiu Wang Zi Xun· 2025-08-05 07:35
Core Insights - The research reveals the hybrid origin of potatoes, tracing back to an ancient crossbreeding event between the tomato group and the solanum group approximately 9 million years ago, leading to the formation of tubers [1][3][7] - The study provides a new theoretical perspective for potato genetic breeding, highlighting the genetic contributions from both parent groups and the unique evolutionary advantages of potatoes [1][6][7] Group 1: Origin and Evolution - Potatoes are the third most important staple crop globally, originating from South America, and are known for their high nutritional value and adaptability [2] - The potato group, which includes cultivated potatoes and 107 wild species, is closely related to the tomato group and the solanum group, with molecular evolution analysis indicating a closer relationship between potatoes and tomatoes [2][3] - The hybridization event that led to the formation of potatoes involved a genetic contribution ratio of approximately 40% from tomatoes and 60% from solanum [3] Group 2: Genetic Mechanisms - The formation of tubers in potatoes is attributed to the recombination of alleles from both parent species, with key genes identified that control tuber formation and underground stem growth [4][5] - The main regulatory gene for tuber formation, SP6A, is derived from the tomato group, while the gene IT1, which regulates underground stem growth, comes from the solanum group [5] Group 3: Adaptation and Diversity - The genetic diversity within the potato group is characterized by a "mosaic" pattern, where approximately 24% of the genetic components are randomly fixed from different parent alleles, allowing for phenotypic variability [6] - The tuber formation provides potatoes with advantages for underground survival, enabling them to store water and starch, and allowing for asexual reproduction through tuber sprouts [6] - The unique genetic makeup and tuber formation have allowed potatoes to thrive in harsh environments, particularly during the uplift of the Andes, leading to rapid species diversification and strong hybrid vigor [6][7]