Abstract

Brassica rapa L. is a valuable and widespread species, but its cultivation in risk farming areas requires high-quality cold-hardy varieties to be developed. Mechanisms of the cold stress response in plants involve expression of numerous genes, including ribosomal ones, and are related to plant chromosome variability. FISH- and PCR-based methods were used to study intraspecific chromosome variability in the number and localization of 45S and 5S rDNA clusters and also to examine a set of molecular markers associated with cold-hardiness in winter B. rapa cultivars from high-risk farming areas. Several SSR (Na10-CO3 and BrgMS5339-1) and SCAR (BoCCA1-F/BoCCA1-1R1 and BoCCA1-F/BoCCA1-2R1) markers were identified as suitable for diagnosing cold-resistant and cold-susceptible genotypes in B. rapa. Compared with fodder cultivars, oilseed and leaf cultivars were shown to have more molecular markers associated with cold-hardiness and a higher level of polymorphism for the chromosomal distribution of 45S and 5S rDNAs, including chromosome heteromorphism. Thus, the least cold-resistant genotypes were found to display the lowest level of chromosome variability in the distribution of the 45S and 5S rDNA clusters and vice versa. The findings could be useful for the development of new cold-tolerant B. rapa varieties.

中文翻译：

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甘蓝型油菜抗寒性的基因组标记

摘要

甘蓝型油菜（Brassica rapa L.）是一种有价值的且广泛分布的物种，但要在危险的耕种地区种植，需要开发高质量的抗寒品种。植物冷胁迫反应的机制涉及许多基因的表达，包括核糖体基因，并且与植物染色体变异有关。基于FISH和PCR的方法用于研究45S和5S rDNA簇的种内染色体变异性和定位，还研究了与高风险农业中冬季B. rapa品种的耐寒性相关的一组分子标记地区。鉴定出几种SSR（Na10-CO3和BrgMS5339-1）和SCAR（BoCCA1-F / BoCCA1-1R1和BoCCA1-F / BoCCA1-2R1）标记适用于诊断耐寒和易感基因型芜菁。与饲料品种相比，油籽和叶片品种显示出更多的与抗寒性相关的分子标记，并且45S和5S rDNA的染色体分布具有更高的多态性，包括染色体异质性。因此，发现最不耐寒的基因型在45S和5S rDNA簇的分布中表现出最低水平的染色体变异性，反之亦然。该发现可能对开发新的耐寒B. rapa品种有用。