ICAR-Indian Agricultural Research Institute, New Delhi, India.
Amity Institute of Biotechnology, Amity University, Noida, India.
J Appl Genet. 2022 Dec;63(4):651-662. doi: 10.1007/s13353-022-00715-x. Epub 2022 Aug 16.
Sweet corn possessing recessive shrunken2 (sh2) gene is popular worldwide. Traditional sweet corn is poor in vitamin A and vitamin E. Plant breeders during the selection of sweet corn genotypes mainly emphasize on plant architecture and yield. Seed germination and seedling vigour play important role for early establishment in field, thereby increasing yield and income. Here, we analysed a set of 15 sh2-based biofortified sweet corn inbreds with crtRB1 (β-carotene hydroxylase1) and vte4 (γ-tocopherol methyltransferase) genes and three traditional sh2-based sweet corn inbreds for nutritional quality, seed vigour and various physico-biochemical traits. The newly developed inbreds possessed significantly higher provitamin A (proA: 15.60 µg/g) and vitamin E [α-tocopherol (α-T): 20.42 µg/g] than the traditional sweet corn inbreds (proA: 2.51 µg/g, α-T: 11.16 µg/g). The biofortified sweet corn inbreds showed wide variation for germination (80.67-87.33%), vigour index-I (2097.17-2925.28 cm), vigour index-II (134.27-216.19 mg) and electrical conductivity (10.19-13.21 μS cm g). Wide variation was also observed for dehydrogenase (1.29-1.59 OD g ml), super oxide dismutase (4.01-9.82 g), peroxidase (11.66-16.47 μM min g), esterase (22.98-34.76 nM min g) and α-amylase (5.91-8.15 OD g ml). Enrichment of proA and vitamin E in sweet corn did not affect seed vigour and physico-biochemical traits. Correlation analysis revealed that electrical conductivity and α-amylase activity was the reliable indicator for assessing seed germination and vigour. The study identified superior biofortified sweet corn genotypes that would contribute to better vigour and establishment in field. This is the first report of analysis of biofortified sweet corn genotypes for seed vigour and physico-biochemical traits.
甜玉米含有隐性皱缩 2 号(sh2)基因，在世界范围内广受欢迎。传统甜玉米中维生素 A 和维生素 E 含量较低。在甜玉米基因型的选择过程中，植物育种者主要强调植物结构和产量。种子萌发和幼苗活力对田间早期建立起着重要作用，从而提高产量和收入。在这里，我们分析了一组含有 crtRB1（β-胡萝卜素羟化酶 1）和 vte4（γ-生育酚甲基转移酶）基因的基于 sh2 的 15 个生物强化甜玉米自交系和三个传统的基于 sh2 的甜玉米自交系，用于营养质量、种子活力和各种生理生化特性。新开发的自交系比传统的甜玉米自交系具有更高的前维生素 A（proA：15.60μg/g）和维生素 E[α-生育酚（α-T）：20.42μg/g]（proA：2.51μg/g，α-T：11.16μg/g）。生物强化甜玉米自交系的发芽率（80.67-87.33%）、活力指数-I（2097.17-2925.28cm）、活力指数-II（134.27-216.19mg）和电导率（10.19-13.21μScmg）差异较大。脱氢酶（1.29-1.59ODgml）、超氧化物歧化酶（4.01-9.82g）、过氧化物酶（11.66-16.47μMming）、酯酶（22.98-34.76nMming）和α-淀粉酶（5.91-8.15ODgml）也有很大差异。甜玉米中 proA 和维生素 E 的富集并不影响种子活力和生理生化特性。相关分析表明，电导率和α-淀粉酶活性是评估种子发芽和活力的可靠指标。该研究鉴定了具有优良活力的生物强化甜玉米基因型，这将有助于更好地在田间建立。这是首次分析生物强化甜玉米基因型的种子活力和生理生化特性的报告。
