Saha Partha, Ghoshal Chandrika, Saha Namita Das, Verma Aakriti, Srivastava Mohita, Kalia Pritam, Tomar Bhoopal Singh
Division of Vegetable Science, Indian Council of Agricultural Research-Indian Agricultural Research Institute, New Delhi, India.
Centre for Environment Science and Climate Resilient Agriculture, Indian Council of Agricultural Research-Indian Agricultural Research Institute, New Delhi, India.
Front Plant Sci. 2021 Aug 23;12:603600. doi: 10.3389/fpls.2021.603600. eCollection 2021.
Cauliflower is an important extensively grown cool season vegetable in India. Black rot and downy mildew are major devastating diseases reducing yield and quality of the crop. To tackle these through host plant resistance, a marker-assisted backcross breeding method was followed to pyramid a black rot-resistant gene () and a downy mildew-resistant gene () from donors BR-161 and BR-2, respectively, into the background of Pusa Meghna cauliflower cultivar. Marker-assisted backcross breeding was followed up to BC generation using SCAR marker ScOPO-04 and SSR marker BoGMS0624 for black rot and downy mildew resistance genes in foreground selection, respectively. In background selection, at each stage of backcrossing, 47 parental polymorphic SSR markers were used. The graphical genotyping of the five two-gene () homozygous BCF plants showed an average recovery of 85.44% of the Pusa Meghna genome with highest genome recovery of 91.7%. The genome contribution of donor parents (BR-161 and BR-2) was 8.26 with 6.34% of residual heterozygousity. The backcross derived pyramided lines BCF and BCF showed high resistance to both the diseases and exhibited higher yield and vitamin C content as compared with recipient parent Pusa Meghna. It is, therefore, evident from this study that resistant genes can be introgressed successfully into a Pusa Meghna cultivar without any yield penalty, benefitting farmers with reduced input cost and consumers with chemical residue free produce. Besides, the pyramided lines carrying dominant resistant genes can be exploited in a hybridization programme to develop hybrid(s) in cauliflower.
花椰菜是印度广泛种植的一种重要的冷季蔬菜。黑腐病和霜霉病是主要的毁灭性病害，会降低作物的产量和品质。为了通过寄主植物抗性来应对这些病害，采用了标记辅助回交育种方法，将来自供体BR - 161和BR - 2的黑腐病抗性基因（）和霜霉病抗性基因（）分别导入普萨·梅格纳花椰菜品种的背景中。在前景选择中，分别使用SCAR标记ScOPO - 04和SSR标记BoGMS0624对黑腐病和霜霉病抗性基因进行标记辅助回交育种，直至BC代。在背景选择中，在回交的每个阶段，使用47个亲本多态性SSR标记。对5个双基因（）纯合的BCF植株进行图形基因分型，结果表明普萨·梅格纳基因组的平均恢复率为85.44%，最高基因组恢复率为91.7%。供体亲本（BR - 161和BR - 2）的基因组贡献率为8.26，残留杂合度为6.34%。回交衍生的聚合系BCF和BCF对这两种病害均表现出高抗性，与受体亲本普萨·梅格纳相比，产量和维生素C含量更高。因此，从这项研究中可以明显看出，抗性基因可以成功导入普萨·梅格纳品种，而不会对产量造成任何损失，这对农民来说降低了投入成本，对消费者来说则提供了无化学残留的产品。此外，携带显性抗性基因的聚合系可用于杂交计划，以培育花椰菜杂交种。
