Vianello Brondani Rosana Pereira, Zucchi Maria Imaculada, Brondani Claudio, Nakano Rangel Paulo Hideo, De Oliveira Borba Tereza Cristina, Rangel Priscila Nascimento, Magalhães Mara Rubia, Vencovsky Roland
Laboratório de Biotecnologia Vegetal, Embrapa-CNPAF, C.P. 179, 74001-970 GO, Goiânia, Brazil.
Genetica. 2005 Nov;125(2-3):115-23. doi: 10.1007/s10709-005-4916-4.
The existence of Oryza glumaepatula is threatened by devastation and, thus, the implementation of conservation strategies is extremely relevant. This study aimed to characterize the genetic variability and estimate population parameters of 30 O. glumaepatula populations from three Brazilian biomes using 10 microsatellite markers. The levels of allelic variability for the SSR loci presented a mean of 10.3 alleles per locus and a value of 0.10 for the average allelic frequency value. The expected total heterozygosity (H(e)) ranged from 0.63 to 0.86. For the 30 populations tested, the mean observed (H(o)) and expected heterozygosities (H(e)) were 0.03 and 0.11 within population, respectively, indicating an excess of homozygotes resulting from the preferentially self-pollinating reproduction habit. The estimated fixation index ( (IS) ) was 0.79 that differed significantly from zero, indicating high inbreeding within each O. glumaepatula population. The total inbreeding of the species ((IT) ) was 0.98 and the genetic diversity indexes among populations, (ST) and (ST), were 0.85 and 0.90, respectively, indicating high genetic variability among them. Thus, especially for populations located in regions threatened with devastation, it is urgent that in situ preservation conditions should be created or that collections be made for ex situ preservation to prevent loss of the species genetic variability.
稻叶野生稻的生存受到破坏的威胁，因此，实施保护策略极为重要。本研究旨在利用10个微卫星标记对来自巴西三个生物群落的30个稻叶野生稻种群的遗传变异性进行表征，并估计其种群参数。SSR位点的等位基因变异水平平均每个位点有10.3个等位基因，平均等位基因频率值为0.10。预期总杂合度（H(e)）范围为0.63至0.86。对于测试的30个种群，种群内观察到的平均杂合度（H(o)）和预期杂合度（H(e)）分别为0.03和0.11，这表明由于优先自花授粉的繁殖习性导致纯合子过剩。估计的固定指数（(IS)）为0.79，与零有显著差异，表明每个稻叶野生稻种群内存在高度近亲繁殖。该物种的总近亲繁殖系数（(IT)）为0.98，种群间的遗传多样性指数（(ST)）和（(ST)）分别为0.85和0.90，表明它们之间存在高度的遗传变异性。因此，特别是对于位于受到破坏威胁地区的种群，迫切需要创造原地保护条件或进行异地保护收集，以防止物种遗传变异性的丧失。
