Involvement of ethylene in sex expression and female flower development in watermelon (Citrullus lanatus)

Inheritance of sex forms in watermelon (Citrullus lanatus)

“…In this study, the critical stage for flower initiation for the spring-summer experiment occurred in the spring when the day light was short and temperatures were low whereas the critical stage for flower initiation for the summer-autumn experiment occurred in the summer during which the day light was long and the average temperature was high. Therefore, our results agree with the pervious study on sex expression in the Cucurbitaceae family, in which the authors showed that short days and low temperatures inhibited the development of staminate flowers and increases the number of pistillate flowers per plant while long days and high temperatures promoted the development of staminate flowers (Manzano et al, 2014).…”

“…In recent studies, the environmental factors such as light intensity, photoperiod and temperature have been shown to influence sex expression in watermelon (Manzano et al, 2014). Short days, low light intensity and cold night temperature promote the development of pistillate flowers, and the production of staminate flowers will be increased in contrary conditions (Rudich and Peles, 1976;Peñaranda et al, 2007;Wien, 1997).…”

“…Short days, low light intensity and cold night temperature promote the development of pistillate flowers, and the production of staminate flowers will be increased in contrary conditions (Rudich and Peles, 1976;Peñaranda et al, 2007;Wien, 1997). Manzano et al (2014) demonstrated that pistillate flowers require more ethylene to develop than staminate flowers, but interestingly, ethylene treatments in the shoot apex inhibit the development of pistillate flowers. In conclusion, these studies illustrated that environment and hormone levels can regulate sex expression in watermelon, but no research on environmental factors or hormone levels influencing sex forms has been reported.…”

“…However, until now, little progress has been made in the research on inheritance of sex form in watermelon. One of the challenges in studying sex inheritance in watermelon is that besides the genetic elements, environmental conditions and hormone levels also influence sex expression in watermelon (Rudich and Peles, 1976;Rudich and Zamski, 1985;Salman-Minkov et al, 2008;Manzano et al, 2014).…”

Dioecy inAmborella trichopoda:evidence for genetically based sex determination and its consequences for inferences of the breeding system in early angiosperms

“…Secondly, we found a variable proportion of bisexual flowers on some predominantly male individuals in both ex situ and in situ populations. Sexual instability is a common phenomenon in dioecious plant species, and many exogenous, environmental and demographic factors are known to affect sex ratios, including plant hormones (Durand and Durand, 1991;Papadopoulou and Grumet, 2005), non-methylable nucleotide analogues (Janousek et al, 1996), temperature (Manzano et al, 2014), pathogens (Scutt et al, 1997), timing of seed set (Freeman et al, 1994) and population structure (Stehlik et al, 2008). Some of these factors strongly suggest the involvement of epigenetic mechanisms operating in sex determination, and sexual instability in A. trichopoda may therefore involve such factors, operating either at, or downstream of, sex-determining loci.…”