Protogyny


Also found in: Dictionary, Medical.
Related to Protogyny: protandry

protogyny

[prō′täj·ə·nē]
(physiology)
A condition in hermaphroditic or dioecious organisms in which the female reproductive structures mature before the male structures.

Protogyny

 

a state in which the stigmata of the pistils ripen earlier than the pollen of a plant. Protogyny is an adaptation to cross-pollination (seeDICHOGAMY and ).

Mentioned in ?
References in periodicals archive ?
The longevity of coenanthia is associated not only with protogyny but also with sequential flower anthesis, and long duration of stigmatic receptivity (female phase) and pollen release (male phase).
Gardner (1982) suggested that protogyny occurs almost without exception in Tillandsia subgenus Tillandsia, including T.
The quantiles of day of female versus male emergence were positively correlated ([F.sub.1,7] = 289.5, P < 0.0001, [r.sup.2] = 0.976; y = 0.996x - 0.081), and the slope of 0.996 for the regression equation indicated that there was no evidence for protandry or protogyny.
However, the sex allocation pattern of various populations of spotted sand bass appear to vary from functional gonochorism to strict protogyny (Hovey and Allen 2000; Hovey et al.
Selecting for low ASI or even protogyny (negative ASI) under optimal conditions, as proposed by Westgate (1997), should avoid the delicate application of stress, but is likely to be ineffective because of the strong G x T effects and absence of relationship between yield under optimal and stressed treatments.
The direction of sex change (female to male; protogyny; male to female; protandry) is fairly well explained by the size-advantage model (Ghiselin, 1969), especially in fishes and crustaceans, two groups in which sequential hermaphroditism is relatively common (Warner, 1975).
In this case, protandry would be expected to select for female-biased allocation in early- compared to late-opening flowers (and protogyny for the opposite pattern).
Hermaphroditism in groupers can be expressed in 1 of 2 ways: as simultaneous, when individuals are capable of reproducing as both male and female, or sequential (the most common mode), when sex change is made from female to male (protogyny) (Smith, 1965; Shapiro, 1987; DeMartini et al., 2011; Wakefield et al., 2015).
Diverging results were found in tests developed by Mussury and Fernandes (2000) in the municipality of Dourados, Brazil, with cultivar CTC-4, and by Delaplane and Mayer (2000), in Georgia, USA, in which they concluded that, when the flower opens, its stigma is already receptive but the anthers are not yet dehiscent, verifying protogyny in the flowers.
Although our experiments were not done with inbreds, poor synchronization of pollen shed with silking in seed fields could result in situations where pollen becomes available when silks are older and less receptive, in a situation analogous to protogyny. Maximum kernel set will require pollen availability at sufficient intensities as well as optimum pollination timing (Bassetti and Westgate, 1993b, Carcova et al., 2000).