Environmental Variation in Seed Mass in Sanguisorba Minor

Abstract

ABSTRACT: Seed mass is an important characteristic of seed quality because larger seeds contain more resources and are likely to exhibit greater vigor than smaller seeds, characteristics that are commonly targeted in plant breeding programmes. Seed mass variation in 359 populations (accessions) of Sanguisorba minor were evaluated across its geographical range in Iran. In addition, the seed and germination parameters of 13 populations that had been stored for 12 years at 4°C in the Natural Resources Gene Bank of Iran were analysed. Seed mass among the 359 populations varied from 1.4g to 14.5g with an average of 5.65g. In this study, the seed mass variation was compared with eco-geographical variables across the original habitats of S. minor . An increase in the maximum temperature of the warmest month, annual precipitation, precipitation of the wettest month, precipitation of the wettest quarter and precipitation of the coldest quarter led to increases in seed mass. Smaller seeds were produced in the hotter and drier environments located in the center of Iran, and in wetter sites. Significant differences in seed traits were found among the 13 stored populations of S. minor and seed germination was positively corrrelated with seed mass (R2 = 0.9). The highest germination percentage after 12 years of storage was obtained in the Hamedan (75%) and Chaharmahal and Bakhtiari (74%) populations, which had heavier and larger seeds. The positive correlation between longevity in ex-situ facilities and seed mass, suggests heavier seeds may have an advantage during storage and for use in breeding programmes.