Comparative meiosis and cytogenomic analysis in euploid and aneuploid hybrids of Urochloa P. Beauv
Comparative meiosis and cytogenomic analysis in euploid and aneuploid hybrids of Urochloa P. Beauv
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DOI：
10.1007/s10577-019-09616-y
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发表时间：
2019-12-01
影响因子：
2.6
通讯作者：
Techio, Vania Helena
中科院分区：
文献类型：
--
作者：
da Rocha, Mara Jane;Chiavegatto, Raquel Bezerra;Techio, Vania Helena
熊果草属包括目前在热带地区用作牧场的大多数重要牧草和杂交种。细胞遗传学分析发现了一些非整倍体杂交种，为遗传育种提供了新的前景。本研究的目的是分析Ruzizisis×Decumbens和Uu ruziziensis×brizantha的整倍体(2n=4x=36)和非整倍体(2n=4x=36+2)杂种的减数分裂行为。随后，通过GISH对涉及配对构型和异常的染色体和各自的基因组进行了鉴定，重点跟踪了非整倍体杂交的Ruziziensis x Decumbens((BBBB2)-B-1-B-2-B-2基因组)中额外染色体的行为。与整倍体杂交种相比，非整倍体杂交种的单价体出现频率更高，二价体减少，不规则指数更高。与整倍体杂交种相比，非整倍体杂交种的单价体频率降低，二价体和三价体频率增加，异常率降低。减数分裂异常率和配对构型受双亲的基因型和三体的影响。非整倍体杂种的B-1和B-2基因组的染色体参与了组内、组内和组内单价体、二价体和多价体的形成。一般来说，基因组的染色体分离时间是不同的，因为B-1基因组的染色体分离较慢。
The genus Urochloa includes most of the important grasses and hybrids currently used as pastures in the tropical regions. Cytogenetic analyzes have identified some aneuploid hybrids that provide new perspectives for genetic breeding. The objective was to analyze the meiotic behavior in euploid (2n = 4x = 36) and aneuploid (2n = 4x = 36 + 2) hybrids of U. ruziziensis x U. decumbens and U. ruziziensis x U. brizantha. Later, the chromosomes and respective genomes involved in pairing configurations and abnormalities were identified through GISH, with an emphasis on tracking the behavior of the additional chromosomes in the aneuploid hybrid U. ruziziensis x U. decumbens ((BBBB2)-B-1-B-2-B-2 genomes). The aneuploid U. ruziziensis x U. decumbens shows a higher frequency of univalents, reduction of bivalents, and higher index of irregularities compared with the euploid hybrid. For the aneuploid U. ruziziensis x U. brizantha, there was a reduction in the frequency of univalents, an increase in bivalent and trivalent rates and a lower frequency of abnormalities when compared with the euploid hybrid. The rates of meiotic abnormalities and pairing configurations are parental genotype-dependent and influenced by trisomy. The chromosomes of the B-1 and B-2 genomes of the aneuploid hybrid (U. ruziziensis x U. decumbens) are involved in the formation of univalents, bivalents, and multivalents in inter-, intra- and inter-intragenomic pairings. In general, the segregation times of chromosomes of the genomes are different, since the chromosomes of the B-1 genome segregate more slowly.