Principle component analysis and determining relationships between the traits of native genotypes of Russian olive in Kerman province

Russian olive (Senjed) is planted in a large area in Iran, and at the same time, there are limited natural habitats for its species. This elder tree can be found in different types of soils and moisture conditions, but preferably it grows better in flood plains and humid coastal areas. Russian olive has a special place as one of the important products of Kerman Province. The area under cultivation and the amount of its production in Kerman are 309 hectares and 1100 metric tons, respectively. In this province, native trees are mainly cultivated along streams and on the edge of fields due to the deliciousness of their fruits. In spite of the wide variety and potential of it, there is less information available on the number of species and the genetic diversity of local genotypes. This study, as a preliminary investigation, showed the existence of high morphological diversity in the native Russian olive genotypes of the province, which reveals the importance of using them in future multi-breeding programs.

In this research, six qualitative traits include fruit shape, fruit aroma and flavor, fruit skin color, fruit ripening date, flowering date, and leaf shape, and fourteen quantitative traits including panicle length, panicle width, petiole length, petiole width, thorn length, thorn width, fruit length, fruit width, seed length, seed width, fruit tail length, fruit tail width, fruit weight, and seed weight were studied between 22 Russian olive native genotypes from Sirjan, Bardsir and Kerman regions.

The results showed the existence of many traits among genotypes. The average fruit length was 1.87 cm, fruit diameter 1.12 cm, fruit weight 1.49 grams, seed weight 0.52 grams, leaf length 4.27 cm and leaf width 2.48 cm. The highest fruit weight and fruit quality and flavor were reported in genotype number (4) of Mahmoudabad, Sirjan. The highest positive correlation coefficient at the probable level (p<0.01) was observed in petiole length and spine length (r=0.669), petiole length and fruit tail length (r=0.601), and fruit length and fruit diameter (r=0.584). Analyzing into main components in qualitative traits showed that the first two components explained 62% of the total changes. In quantitative traits, the first five components included 74.77% of the total changes. Based on the dendrogram of the scatterplot of quantitative and qualitative traits, all genotypes were divided into three separate groups. In the present research, the classification of masses based on quantitative traits did not follow their geographical distribution.

The highest fruit weight belonged to the genotype of Mahmoud Abad Sirjan, which is a tropical region of Sirjan, and it had a sweet taste and a good aroma. The highest correlation values of traits were observed in PC1 between the traits of flowering date, leaf shape, leaf, fruit and seed dimensions, as well as seed weight. The presence of superior leaf traits and the subsequent improvement programs on them can expand the scope of use of elderberry from the fruit-only state. Environmental conditions and being at different heights above sea level do not play a significant role in the classification of genotypes.