The author acknowledges the assistance of Richard Craig and Gregory Anderson in the development of techniques for determining ploidy in plants. The cost of publishing this paper was defrayed in part by the payment of page charges. Under
Most of the U.S. watermelon market is seedless (triploid) fruit. Because so much of the market depends on triploids, it is important to understand the effect ploidy plays on quality traits for this crop. Traits such as size and yield have been
; Chen and Yu, 2013 ; Hegarty and Hiscock, 2008 ; Laport and Ng, 2017 ; Madlung, 2013 ). For plant breeders, knowledge of ploidy is particularly important because it influences reproductive compatibility, fertility of hybrids, and gene expression
( Hättenschwiler and Körner, 2003 ). In attempts to address shot-hole symptoms and the weedy tendencies in this species, we created chromosome doubled forms of the cultivar Schipkaensis. Although many studies have compared morphological variability in ploidy series
exception of K. polifolia that was tetraploid (2 n = 4 x = 48). However, that study only examined material from one or two plants per species to determine ploidy, and in the case of K. angustifolia , only samples from North Carolina were obtained as
have not been analyzed for ploidy or genome size. Improved knowledge of chromosome numbers and ploidy levels of key species and cultivars would be a valuable resource for further breeding and improvement of Camellia . Analyses of other closely related
for persimmons with these two ploidy levels overlap in Kentucky ( Baldwin and Culp, 1941 ). Fig. 1. Reported tetraploid and hexaploid American persimmon populations based on the data of Baldwin and Culp (1941) and data in the current study. Most
chromosomal systems that allow permanent propagation of odd ploidies ( Grant, 1981 ). In cases where triploids set seed sexually, they can serve as a genetic bridge, allowing gene exchange between diploids and tetraploids, both in natural populations and in
. Polyploidy occurs in the genus Lonicera ( Ammal and Saunders, 1952 ; Solov’eva and Plekhanova, 2003 ). Ploidy levels and genome sizes play important roles in plant evolution ( Soltis et al., 2003 ). The 2C nuclear DNA amount of Lonicera varies 6-fold
, accurate and specific knowledge of ploidy levels of species and cultivars is important information for magnolia breeders. The genus Magnolia comprises more than 250 species belonging to various sections within three subgenera ( Figlar and Nooteboom, 2004