Relevance of unilateral and bilateral sexual polyploidization in relation to intergenomic recombination and introgression in Lilium species hybrids
Relevance of unilateral and bilateral sexual polyploidization in relation to intergenomic recombination and introgression in Lilium species hybrids
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DOI：
10.1007/s10681-009-9998-0
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发表时间：
2010-01-01
期刊：
影响因子：
1.9
通讯作者：
Van Tuyl, Jaap M.
中科院分区：
文献类型：
--
作者：
Khan, Nadeem;Barba-Gonzalez, Rodrigo;Van Tuyl, Jaap M.
通过与亚洲百合（AA）亲本的回交以及与LA杂种的姊妹交，诱导出2n = 2x = 24的麝香百合（Longiflorum）×亚洲百合（LA）和东方×亚洲百合（OA）种间杂种F1的有性多倍体。回交后代大多数为三倍体，同胞交配后代为四倍体或近四倍体。利用基因组原位杂交技术（GISH）研究了单倍性多倍体化后的LA和OA杂种BC 1群体中的基因组间重组。共分析了63个LA（LA × AA和AA × LA）和53个OA杂交体。LA杂种是通过2n配子作为2n卵或2n花粉的功能而产生的，而OA杂种是通过二倍体OA基因型的功能性2n花粉而产生的。在这两种类型的杂交中，大多数后代都是通过功能性2n配子的第一次分裂休眠（FDR）机制产生的，无论是否有交叉。然而，有9个LA-和4个OA-基因型，其中不确定减数分裂暂停（IMR）是2n配子形成的机制。以GISH为基础，测定了长穗菊和东方基因组向亚洲基因组的总渗入量。大多数的BC后代表现出重组和重组的量是较高的LA杂交相比，OA杂交。基因组间重组也确定在16个植物的同胞交配的LA杂种父母双方都贡献了2n配子的细胞学。基于这些结果的性质，种间杂交百合从单和双边性多倍体化导致异源三倍体和异源四倍体形成的背景下，基因渗入和基因组间重组进行了讨论。
Sexual polyploids were induced in diploid (2n = 2x = 24) interspecific F1 hybrids of Longiflorum x Asiatic (LA) and Oriental x Asiatic (OA) Lilium hybrids by backcrossing to Asiatic (AA) parents as well as by sib-mating of the F1 LA hybrids. A majority of the BC1 progenies were triploid and the progenies from sib-mating were tetraploid or near tetraploids. Genomic in situ hybridization (GISH) technique was applied to assess the intergenomic recombination in the BC1 populations of LA and OA hybrids obtained after unilateral sexual polyploidization. A total of 63 LA (LA x AA and AA x LA) and 53 OA hybrids were analysed. LA hybrids were originated through the functioning of 2n gametes either as 2n eggs or 2n pollen while those of OA hybrids originated through functional 2n pollen of diploid OA genotype. In both type of crosses, a majority of the progenies had originated through First Division Restitution (FDR) mechanism of functional 2n gamete either with or without a cross over. However, there were nine LA- and four OA-genotypes where Indeterminate Meiotic Restitution (IMR) was the mechanism of 2n gamete formation. Based on GISH, total amount of introgression of Longiflorum and Oriental genome into Asiatic genome was determined. Most of the BC progenies exhibited recombination and the amount of recombination was higher in LA hybrids as compared to OA hybrids. Intergenomic recombination was also determined cytologically in the 16 plants of sib-mated LA hybrids where both parents had contributed 2n gametes. Based on these results the nature of interspecific lily hybrids obtained from uni- and bilateral sexual polyploidization leading to allotriploid and allotetraploid formation is discussed in the context of introgression and intergenomic recombination.