Harun Arrashid, Song Shipeng, You Xixi, Liu Hui, Wen Xiaopeng, Fang Zhongming, Cheng Zhihao, Chen Chunli
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-bioengineering, College of Life Science, Guizhou University, Guiyang, Guizhou, China.
National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China.
Front Plant Sci. 2024 Dec 6;15:1493776. doi: 10.3389/fpls.2024.1493776. eCollection 2024.
Pitaya (; 2n=22) is an important fruit crop from the family, originally domesticated in Mexico and the USA, and is now widely cultivated for its nutritional benefits. It is characterized by its distinctive triangular-shaped stems and large, showy flowers, thriving in arid and semi-arid environments, particularly in hot, dry climates. However, systematic chromosomal studies, including chromosomal mapping of cytogenetic markers in pitaya, are limited, presenting challenges for its cytogenetic improvement. To address this issue, we designed oligo-barcodes specific to thirty-three chromosome regions based on the pitaya reference genome and applied them to both pitaya and cactus (; 2n=22) for oligo-barcodes mapping, karyotyping, and chromosome identification. We utilized FISH technology, employing oligo, rDNA, and tandem repeat probes for chromosomal mapping, identification, and karyotyping of pitaya and related species. We successfully localized oligo-barcodes on eleven pairs of chromosomes in both pitaya and cactus, demonstrating the effectiveness of the synthesized oligo-barcodes. We used two ribosomal DNA (rDNA) probes (45S and 5S) and two tandem repeat probes (GTR11 and STR3) in pitaya (both diploid and tetraploid) and two other species ( and ; 2n=40) for chromosomal mapping. The analysis of rDNA distribution and CMA (Chromomycin A3) banding across different chromosomes in pitaya and cacti highlights the concept of conserved rDNA. This study provides fundamental insights into cytogenetic markers and their localization across different chromosomes in pitaya and other species.
火龙果（2n = 22）是仙人掌科的一种重要水果作物，最初在墨西哥和美国被驯化，现在因其营养价值而被广泛种植。它的特点是茎呈独特的三角形，花朵大且艳丽，在干旱和半干旱环境中生长旺盛，尤其在炎热干燥的气候条件下。然而，包括火龙果细胞遗传标记的染色体图谱绘制在内的系统染色体研究有限，这给其细胞遗传学改良带来了挑战。为了解决这个问题，我们基于火龙果参考基因组设计了针对33个染色体区域的寡核苷酸条形码，并将其应用于火龙果和仙人掌（2n = 22）进行寡核苷酸条形码图谱绘制、核型分析和染色体鉴定。我们利用荧光原位杂交（FISH）技术，使用寡核苷酸、核糖体DNA（rDNA）和串联重复探针进行火龙果及其相关物种的染色体图谱绘制、鉴定和核型分析。我们成功地在火龙果和仙人掌的11对染色体上定位了寡核苷酸条形码，证明了合成的寡核苷酸条形码的有效性。我们在火龙果（二倍体和四倍体）以及另外两个物种（2n = 40）中使用了两种核糖体DNA（rDNA）探针（45S和5S）和两种串联重复探针（GTR11和STR3）进行染色体图谱绘制。对火龙果和仙人掌不同染色体上rDNA分布和CMA（放线菌素A3）带型的分析突出了保守rDNA的概念。这项研究为火龙果和其他物种不同染色体上的细胞遗传标记及其定位提供了基本见解。
