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

Ecological Processes

Chandra Mohan Sharma¹  Vinod Prasad Khanduri¹  Arun Sukumaran² 

[1] Department of Forestry, College of Forestry, VCSG Uttarakhand University of Horticulture and Forestry, Ranichauri, 249199, Tehri Garhwal, Uttarakhand, India;Department of Forestry, College of Forestry, VCSG Uttarakhand University of Horticulture and Forestry, Ranichauri, 249199, Tehri Garhwal, Uttarakhand, India;Present Address: State Farming Corporation of Kerala, Chithalvetty Estate, Kalanjoor Kollam, Kerala, India;

关键词: Gender;    Sex expression;    Gender segregation;    Strobili;    Pre-fertilisation;    Monoecy;    Dioecy;   

DOI  :  10.1186/s13717-021-00311-7

来源: Springer

【 摘 要 】

BackgroundThe 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.MethodsAn 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.ResultsFive 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.ConclusionsThe size of the tree, resource availability, sex allocation, plant architecture, gender segregation in crowns, and habitat conditions are the prominent causes for gender plasticity.

【 授权许可】

CC BY