WHITE FLOWER COLOR IN RAPE (BRASSICA NAPUS) ASSOCIATED WITH A RADISH (RAPHANUS SATIVUS) CHROMOSOME

Abstract

The inheritance of flower color was investigated in progeny from crosses between a normal, yellow flowering rape strain (Brassica napus L.) and a white flowering strain developed at the University of Manitoba by backcrossing the white flower color from Raphanobrassica into B. napus. The chromosome number of all yellow flowering plants examined was normal (2n = 38), whereas all white flowering plants examined contained a single or a pair of small radish (Raphanus sativus L.) chromosomes each carrying a dominant gene(s) for white flower color. The homozygous white flowering rape strain was in fact an alien addition line (2n = 40) disomic for a pair of radish chromosomes. The transmission and meiotic behavior of this alien chromosome as a univalent was investigated in the progeny of crosses involving the white flowering F1 hybrid. Cytological observations of meiotic metaphase 1 indicated that the univalent should be transmitted with 24.6% of the gametes. This was in agreement with the observed transmission of 24.3% through the female gametes. Transmission through the pollen ranged from 22.1% to 0.7%, the variation in certation depending on the genetic constitution of the pistil and on the time of pollination. The vigor, fertility and true breeding nature of the white flowering strain suggested that the white flower color factor from the radish had been introgressed into the rape genome. Cytological observations were necessary to demonstrate that introgression had not taken place and to aid in the interpretation of the genetic ratios observed.

Male sterility in Brassica napus L. associated with an extra chromosome

“…Presence of alien chromosomes in B. napus has also been observed by Sernyk and Stefansson ( 1982). A pair of Raphanus sativus chromosomes were responsible for a white flower characteristic in B. napus.…”

“…Heterosis for seed yield in hybrid rapeseed (Brassica napus) has been reported by various authors (Sernyk and Stefansson 1983;Buson 1980;Guan 1980;Schuster and Michael 1976;Shiga 1976). Hybrids have shown a 20-40% increase in seed production over their midparents or standard cultivars.…”

Production and characterization of Brassica napus-Raphanus sativus monosomic addition lines mediated by the synthetic amphidiploid "Raphanobrassica"

“…3C, F and Table 4). Kato and Tokumasu (1976) reported that a single dominant gene controlled white petal color in radish, and Sernyk and Stefansson (1982) reported that the B. napus strain added with a R. sativus chromosome developed at University of Manitoba produced white flowers. Therefore, it was assumed that a single dominant gene determining white petal color was located on the g-chromosome of radish.…”

Comparative analysis of the orange versus yellow petal of rapeseed (Brassica napus) using UPLC‐HESI‐MS/MS and transcriptome analysis

“…Sources of rapeseed petal colour variation mainly include natural variation, artificial chemical mutagenesis and transfer from Brassica oleracea . Zhang et al (2007) identified natural mutants of rapeseed with golden yellow petals; Li et al (2001) identified orange‐red petal mutants in cytoplasmic male sterility lines; Sernyk and Stefansson (1982) hybridized white‐flowered B. oleracea with rapeseed to obtain white petal mutant material (2 n = 40). However, the mechanism of petal colour regulation in rapeseed is not fully understood.…”