Inheritance of fruit, foliar and plant habit attributes in Capsicum L.

Authors: Stommel, John; Griesbach, Robert

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2008
Publication Date: 5/1/2008
Citation: Stommel, J.R., Griesbach, R.J. 2008. Inheritance of fruit, foliar and plant habit attributes in Capsicum L. Journal of the American Society for Horticultural Science. 133:396-407.

Interpretive Summary: Considerable variation is available in pepper for fruit and foliage color, shape and size. Pepper plants may also vary in height from very short to very tall. When plant breeders wish to combine various characters in order to develop a new pepper plant, they are often hindered by a lack of knowledge on the inheritance of these characters and the number of genes that influence them. We conducted a genetic study to characterize the inheritance of pepper fruit, leaf and plant size attributes. We found that plant breeders can efficiently combine these different characters into a single plant because the variation which breeders may select from is due mostly to the plants genes and not due to variation caused by the conditions under which the plants are grown. Variation due to the plants genes will be passed on to its offspring whereas variation caused by the environment will not. We also found that some characters were associated with one another. For example, round fruit shape was associated with black fruit color. In this case, selection for round fruit that are green would be difficult. The results will be useful to plant breeders in developing new and improved peppers.

Technical Abstract: Considerable diversity exists in Capsicum L. germplasm for fruit and leaf shape and size, as well as plant habit. Utilizing F1, F2 and backcross generations developed from diverse parental stocks, this report describes the inheritance patterns and relationships between unique foliar characters and diverse fruit and plant habit attributes. Our results demonstrate that pepper fruit color, shape and fruit per cluster were simply inherited with modifying gene action. Broad sense heritability for fruit color and shape and fruit per cluster were high, whereas narrow sense heritability for these characters was moderate to low. Although fruit clustering was simply inherited, the number of fruit per cluster exhibited a quantitative mode of inheritance. High fruit counts per cluster were linked with red fruit color and anthocyanin pigmented foliage. Fruit shape was linked with immature fruit color and inherited independently of mature fruit color. Leaf color, length and plant height were quantitatively inherited. Leaf shape did not vary, but leaf length varied and was positively correlated with leaf width. Broad sense heritability for leaf characters including leaf length, leaf width and leaf color were high. With the exception of leaf width which exhibited low narrow sense heritability, high narrow sense heritability for leaf characters denoted additive gene action. Plant height displayed high broad sense heritability. Moderate narrow sense heritability suggested that additive effects also influence plant height. Analysis of segregating populations demonstrated that red and orange fruit color can be combined with all possible leaf colors from green to black. These results provide new data to clarify and extend available information on the inheritance of Capsicum fruit attributes and provides new information on the genetic control of leaf characters and plant habit.