Genetic diversity and physiological performance of Portuguese wild beet (Beta vulgaris spp. maritima) from three contrasting habitats

Frontiers in Plant Science

Octávio Salgueiro Paulo¹  Carla Maria Ribeiro¹  Carla Pinheiro²  Isabel Evaristo⁴  Cândido Pinto Ricardo⁵  Isa Catarina Ribeiro⁵  Maria Manuela Veloso⁶  Maria Cristina Simões-Costa⁶ 

[1] 3Computational Biology and Population Genomics Group, cE3c – Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências da Universidade de Lisboa;Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa;INIAV-Oeiras, Unidade de Investigação de Biotecnologia e Recursos Genéticos;INIAV-Oeiras, Unidade de Investigação de Sistemas Agrários e Florestais;Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB-UNL);Universidade de Lisboa, Instituto Superior de Agronomia, LEAF;

关键词: biomass;    population structure;    Crop wild relatives;    Physiological characterization;    Allele richness;   

DOI  :  10.3389/fpls.2016.01293

来源: DOAJ

【 摘 要 】

The establishment of stress resilient sugar beets (Beta vulgaris spp. vulgaris) is an important breeding goal since this cash crop is susceptible to drought and salinity. The genetic diversity in cultivated sugar beets is low and the beet wild relatives are useful genetic resources for tolerance traits. Three wild beet populations (Beta vulgaris spp. maritima) from contrasting environments, Vaiamonte (VMT, dry inland hill), Comporta (CMP, marsh) and Oeiras (OEI, coastland), and one commercial sugar beet (Isella variety, SB), are compared. At the genetic level, the use of six microsatellite allowed to detect a total of seventy six alleles. It was observed that CMP population has the highest value concerning the effective number of alleles and of expected heterozygosity. By contrast, sugar beet has the lowest values for all the parameters considered. Loci analysis with STRUCTURE allows defining three genetic clusters, the sea beet (OEI and CMP), the inland ruderal beet (VMT) and the sugar beet (SB). A screening test for progressive drought and salinity effects demonstrated that: all populations were able to recover from severe stress; drought impact was higher than that from salinity; the impact on biomass (total, shoot, root) was population specific. The distinct strategies were also visible at physiological level. We evaluated the physiological responses of the populations under drought and salt stress, namely at initial stress stages, late stress stages and early stress recovery. Multivariate analysis showed that the physiological performance can be used to discriminate between genotypes, with a strong contribution of leaf temperature and leaf osmotic adjustment. However, the separation achieved and the groups formed are dependent on the stress type, stress intensity and duration. Each of the wild beet populations evaluated is very rich in genetic terms (allelic richness) and exhibited physiological plasticity, i.e. the capacity to physiologically adjust to changing environments. These characteristics emphasize the importance of the wild beet ecotypes for beet improvement programs. Two striking ecotypes are VMT, which is the best to cope with drought and salinity, and CMP which has the highest root to shoot ratio. These genotypes can supply breeding programs with distinct goals.

【 授权许可】

Unknown