Genetic parameters and selection indexes for biofortified red leaf lettuce

Abstract: The objective of this work was to determine the genetic parameters and the efficiency of different selection indices for biofortified red leaf lettuce (Lactuca sativa var. crispa) lines with agronomic and nutritional potential. The experiment was carried out in a randomized complete block design with three replicates and 31 crisp-textured and red-tinted leaf lettuce genotypes: the Belíssima cultivar, with a low carotenoid content and rich in anthocyanins; and 30 lines from the cross between the Belíssima and Uberlândia 10000 cultivars, rich in carotenoids and with a low anthocyanin content. The assessed traits were: total green mass (g), stem diameter (cm), leaf count, plant diameter (cm), foliar temperature (°C), soil plant analysis development (SPAD) index, anthocyanin content (mg 100 g-1 sample), and bolting (days after sowing). To estimate selection gains, 12 genotypes were selected through selection indices. The traditional index proposed by Smith & Hazel and the sum of ranks index by Mulamba & Mock provided the highest selection gains in the biofortified lettuce. The coefficient of genotypic determination for leaf count, anthocyanin content, bolting, and SPAD index is of high magnitude.

摘要：本研究旨在明确兼具农艺与营养潜力的生物强化红叶生菜（Lactuca sativa var. crispa，皱叶莴苣）品系的遗传参数，以及不同选择指数的选育效率。本试验采用完全随机区组设计，设置3次重复，共纳入31份皱叶红叶生菜基因型：包括类胡萝卜素含量低但花青素含量丰富的贝莉西玛（Belíssima）品种，以及由贝莉西玛与类胡萝卜素含量高、花青素含量低的乌贝兰迪亚10000（Uberlândia 10000）品种杂交获得的30份品系。本试验评估的性状包括：总鲜绿质量（g）、茎粗（cm）、叶片数、株幅（cm）、叶温（℃）、土壤植物分析发展（SPAD）指数、花青素含量（mg 100 g⁻¹ 样品）以及抽薹期（播种后天数）。为估算选育增益，研究通过选择指数筛选出12份基因型。其中，Smith-Hazel传统选择指数与Mulamba-Mock秩和选择指数在该生物强化生菜中实现了最高的选育增益。叶片数、花青素含量、抽薹期以及SPAD指数的基因型决定系数均处于较高水平。