Gender plasticity uncovers multiple sexual morphs in natural populations of Cedrus deodara (Roxb.) G. Don

Abstract

Background The expression of gender in gymnosperms is challenging because the extent of variability in gender segregations in tree crowns and selection pressure of nature can modify the gender through time. Methods An in-depth investigation on spatial segregation of genders in tree crowns and sex expression of a total of 500 trees in five different natural populations of Cedrus deodara was carried out and verified the occurrence of subdioecious (co-existence of male, female, and monoecious) genders in C. deodara. Results Five different sexual morphs were apparent among the 500 selected individuals as (1) pure male (M): bearing only male strobili in the whole crown with 22.2%; (2) pure female (F): bearing only female strobili in the whole crown with 12.4%; (3) mixed-monoecious (MM): bearing both male and female strobili with 13.6%; (4) predominantly female (PF) with 25.6%; and (5) predominantly male (PM) with 26.2%. The occurrence of multiple sexual morphs resulted from the complex selection pressure, which increased the stability of the populations. The segregation of genders in crown layers deemed to increase the fitness that may be a mechanism for accelerating outcrossing. The results of the study suggest that the subdioecious gender expression in C. deodara is evolved through the monoecy–paradioecy pathway. The production of male strobili revealed non-significant effect of tree sizes whereas a significant effect was observed for the production of female strobili. Our study established that the total pollen and seed outputs in C. deodara changed frequently according to gender expression. Conclusions The size of the tree, resource availability, sex allocation, plant architecture, gender segregation in crowns, and habitat conditions are the prominent causes for gender plasticity.

Pollen production, release and dispersion in Himalayan alder (Alnus nepalensis D. Don.): a major aeroallergens taxa

“…On the contrary, the height and diameter of Pinus roxurghii have a negative significant correlation with pollen grains per tree (Khanduri and Sharma, 2002a), and the height of the tree in Populus and Acer negundo have a negative significant correlation with pollen grains per tree (Molina et al, 1996). The non-significant effect of tree sizes on male cone production and the significant effect on female cone production was reported in Cedrus deodara (Khanduri et al, 2021). In a detailed study of six oaks species, negative correlations were found between pollen grains per anther, the number of anthers per flower, and the number of flowers per catkin.…”

Pollen indices of Cedrus atlantica Manetti populations vary with geographical localities in the Moroccan Atlas Mountains

“…The study of reproduction in C. deodara species has revealed a large variability in pollen and ovule characters (Johri and Vasil 1961;Chowdhury 1961;Konar and Oberoi 1969;Owens 1995a, 1995b;Sharma 2002, 2009), as well as in the sexual expression of the tree depending on year, site, and tree size (Khanduri and Sharma, 2010;Sharma and Bhondge 2016;Khanduri et al 2021). Some limited studies have reported significant variability in pollen size of C. atlantica depending on several parameters, including site conditions, genome size, adaptations required for wind pollination, and irregular pollen development (Smith 1923;Derridj et al 1991;Bell et al 2017;Bell et al 2018aBell et al , 2018b.…”

Plant Segregation and Pollen Characteristics of Highland Papaya (Vasconcellea Pubescens A.DC.) Based on Sex Types

“…Investigations have shown several factors alter sex expression in monoecious plants, including sex allocation (Pannell, 2017), environmental pressure, and adaptation to wind pollination (Walas et al, 2018). The tree size also significantly impacts sex expression, with females and monoecious trees often found in higher-diameter classes, which can compensate for a more reproductive investment (Khanduri et al, 2021).…”