Abstract

Strobilanthes virendrakumarana Venu and P. Daniel karyotype was found to be a mixoploid one with 2n = 20 + 0–1B and reveals the karyotype formula as 2 nsm(–) + 18 nm + 0–1B. The plant is endemic to Southern Western Ghats of Kerala. The basic set of chromosomes was found to be x = 10. The plant shows mixoploidy with four different chromosome counts from hypoploid (10 + 0 – 1B), diploid (20 = 0–1B) and hyperploid chromosome complements (30 + 0 – 2B, 40 + 0 – 2B). The karyotype formula of hyperploid cell was 2 nsm(–) + 8 nm + 0–1B. In hypoploid cells with 30 and 40 chromosomes the resulted karyotype formula were 30 nm + 0–2 B and 6 M + 34 nm + 0–2 B respectively. The total chromosome length of diploid complement was 45.34 μm with an average chromosome length of 2.2 μm. The detailed karyomorphometrical analysis of the plant reveals that is a primitive one with symmetric karyotype. The presence of B-chromosomes in the genus Strobilanthes is reporting for the first time. Ploidy level changes may be due to the prolonged flowering periodicity of the plant which enables them to survive by propagating through vegetative mode.

中文翻译：

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Strobilanthes virendrakumarana 混合倍体核型中的 B 染色体

摘要

Strobilanthes virendrakumarana Venu 和 P. Daniel 核型被发现是一个混倍体，其 2 n = 20 + 0–1B 并显示核型公式为 2 nsm(–) + 18 nm + 0–1B。该植物是喀拉拉邦西南部高止山脉特有的植物。发现染色体的基本组是x= 10. 该植物显示出混合倍体，具有亚倍体 (10 + 0 – 1B)、二倍体 (20 = 0–1B) 和超倍体染色体互补物 (30 + 0 – 2B、40 + 0 – 2B) 的四种不同染色体计数。超倍体细胞的核型公式为2 nsm(-) + 8 nm + 0-1B。在具有 30 条和 40 条染色体的亚倍体细胞中，得到的核型公式分别为 30 nm + 0-2 B 和 6 M + 34 nm + 0-2 B。二倍体补体的总染色体长度为45.34 μm，平均染色体长度为2.2 μm。对该植物的详细核型分析表明，这是一种具有对称核型的原始植物。Strobilanthes属中 B 染色体的存在是第一次报道。倍性水平的变化可能是由于植物的开花周期延长，这使它们能够通过营养模式繁殖而存活下来。