Effect of light on seed germination and seedling shape of succulent species from mexico  

作　　者：Joel Flores Claudia González-Salvatierra Enrique Jurado 

机构地区：[1]División de Ciencias Ambientales,Instituto Potosino de Investigación Científica y Tecnológica,A.C.,Camino a la Presa de San José2055,Col.Lomas,4Sección,San Luis Potosí,San Luis Potosí78216,México [2]Facultad de Ciencias Forestales,Universidad Autónoma de Nuevo León,Carretera Nacional,km 145,Linares,N.L.67700,México

出　　处：《Journal of Plant Ecology》2016年第2期174-179,共6页植物生态学报（英文版）

基　　金：Secretaría de Educación Pública-Consejo Nacional de Ciencia y Tecnología(CB-2010-156205).

摘　　要：Aims Light requirements for cactus seed germination have been considered to be associated with their adult plant height and seed mass,but this has not been thoroughly studied for other succulent species.In order to understand seed photosensitivity from desert species belonging to Asparagaceae(subfamily Agavoideae)and Cactaceae,we performed a germination experiment with and without light for 12 species and 2 varieties from 1 species from the Southern Chihuahuan Desert.We also determined if adult growth is totally determined by seedling‘growth form’in cacti.Methods We performed a germination experiment using light and darkness for 13 species from Southern Chihuahuan Desert:10 rosette species(Asparagaceae),as well as 1 globose,1 columnar and 2 varieties from 1 depressed-globose species(Cactaceae).The response variables were seed germination percentage and relative light germination(RLG).In addition,in order to determine if adult-globose cacti could have cylindrical seedlings,we calculated the shape index(height/width ratio)for Coryphanta clavata and Mammillaria compressa.Important Findings All species were considered neutral photoblastic.Eleven species had similar seed germination in both light and dark conditions,and three taxa(M.compressa and the two varieties of Ferocactus latispinus)showed higher germination with light than without it.Agave salmiana,M.compressa and the two varieties of F.latispinus had higher RLG than the other species.Seed mass was an important factor because with higher seed mass there was lower dependence to light.These findings support the hypothesis that small seed mass and light requirements have coevolved as an adaptation to ensure germination.One adult-globose cactus species,M.compressa,and one adult-columnar species,C.clavata,had small seeds and neutral fotoblasticism.Seedlings from these two species exposed to light were cylindrical and those under darkness conditions were columnar.Perhaps seeds from this species are able to germinate in the dark because they produce columnar seedl

关 键 词：ASPARAGACEAE CACTACEAE Chihuahuan Desert photoblasticism seed germination succulent plants 

分 类 号：Q94[生物学—植物学]