Genetic Combining Ability of Petal Shape in Garden Pansy (Viola × wittrockiana Gams) based on Image Analysis

Abstract

Flower appearance is an important target for improvement in garden pansy (Viola × wittrockiana Gams). Flowers of this species consist of three petal types: inferior, lateral, and superior. By means of principal-components (PC) analysis of elliptic Fourier descriptors (EFDs), we estimated the general and specific combining abilities (GCA and SCA) of the floral characteristics of F 1 progeny derived from diallel crosses of four inbred lines. The greatest variation in petal shape was explained by the aspect ratio (the first PC) in each petal type. The second or third PC of each petal type was associated with the curvatures of the various parts of the petal. The highly significant GCA effects indicate the importance of additive genetic variance in the transmission of parental petal characteristics to the progeny. The fact that the SCA mean squares were not significant for aspect ratio and petal area indicates that these characteristics of a single-cross progeny can be sufficiently predicted on the basis of GCA. Significant SCA effects were observed in the curvatures of the distal and proximal parts of lateral and superior petals. Correlation analyses indicated several associations between the shape elements of lateral and superior petals, suggesting that genes for these shape elements may be associated, linked, or pleiotropic in the parents used in this study. We successfully demonstrated the use of EFD-PCA to evaluate the petal shape of garden pansy, and of analyzing combining ability and correlations based on the PC scores of EFDs.

Karyologic and Heterosis Studies of the Artificial Inter- and Intraspecific Hybrids of Viola ×wittrockiana and Viola cornuta

“…In this study, we observed that the leaf area and stomata and flower size of the V. •wittrockiana inbred lines were increased significantly compared with the V. cornuta inbred line, but we observed no distinct differences in leaf shape corresponding to the leaf index between the V. •wittrockiana inbred and the V. cornuta lines. In V. •wittrockiana, additive genetic variance in the transmission of parental petal characteristics (superior and lateral petal ratio and area) to the progeny is extremely important and should be taken into account by breeders (Yoshioka et al, 2006).…”

Flower color digitizing and pigment distribution in garden pansy

“…Pansy is one of the most colorful flowers around the world, success of artificial hybridization among intra-and interspecific by many breeders since the 19th century (Yoshioka et al 2006, Li et al 2014, Du et al 2018). However, little information about pansy flower color measured by colorimeter has been reported until now.…”

Using cameras for precise measurement of two-dimensional plant features: CASS

“…Shape analysis of leaves has used scanned images, for apple, grapevine, Claytonia L., and a mixture of species [2,3,4,5] 1 . Scanners have also been used to analyze the shape of pansy petals [6] and Vitis vinifera L. seeds [7].…”