Selection Almond Superior Genotypes Form F1 Segregated Population of ‘Tuono’ × ‘Shokoufe’ Cultivars

Abstract

The primary steps in breeding programs are identifying and selecting superior fruit trees genotypes. This study was conducted to achieve the most productive, self-compatible, and cold tolerated almond [Prunus dulcis (Mill.)D.A.webb] genotypes, by determining genetic variability of 103 progenies resulted by crossing ‘Tuono’ and ‘Shokoufe’ during two years, 2016-2017 at Meshkin Abad Horticulture Research Station in Karaj (50.9°E, 35. ° 7521 N, 1245 m height, with moderate and cold climates, shallow, calcareous soils, with a pH = 7) according to almond description (Gulcan, 1985) for selecting superior hybrids. The genetic relationship between selected hybrids was carried out by using genetic correlation. Minimum, maximum, and comparing mean results represented hybrids’ variability. Correlations indicated significant positive and negative variability. 20 components of effective traits justified 77.4% of the total variance. Hybrid separation was carried out by clustering analysis using 20 components. In 10th Euclidean distance, hybrids were separated into 17 groups. Fruit, nut, kernel, productivity, and vigor characteristics were the main factors in grouping clusters, respectively. In the first factor, traits including fruit size (0.70), fruit weight (0.880), fruit length (0.741), fruit width (0.769), fruit thickness (0.722), nut weight (0.872), nut length (0.729), nut width (0.795), nut thickness (0.673), kernel weight (0.849), kernel length (0.635) and kernel width (0.837). In the second factor, there were traits including productivity (0.797), number of nuts per tree (0.925), fruit weight per tree (0.932), and nut weight per tree (0.905). In the third factor, traits such as trunk diameter (0.60), the radius of expansion in two directions north-south (0.755) and east-west (0.804), leaf density (0.60), and growth habit (0.60). These third components could justify about 14%, 7%, and 5% of the total variance. The most variable traits were growth habit, high quality, bearing habit, flowering and leafing time, fruit size; date of harvesting, nut shape and the lowest variable trait was kernel taste.

Keywords

• almond
• breeding programs
• hybrid
• morphological traits
• late frost spring