Corm

Abstract: 1 Genotypic variation and plasticity of clonal growth and storage in relation to nutrient availability were examined in 10 clones of a perennial, corm-forming grass (Amphibromus scabrivalvis). The clones (derived from seeds) were each separated into 72 ramets and planted in a glasshouse. Half of all ramets received fertilizer every 2 weeks, while the others received only water. 2 At 11, 20 and 26 weeks, 24 ramets per clone genotype were harvested; number of ramets and corms, and corm, rhizome, root, and shoot dry mass were recorded. Ramet number and rhizome mass were indicators of clonal growth, while corm number and mass were indicators of storage. 3 There were highly significant differences among clones for all traits examined at all ages. The response to nutrient addition showed genotypic variation, but depended on age for at least some traits. 4 Substantial phenotypic plasticity of traits important to clonal growth and storage was exhibited by the clones in response to nutrient availability. Norms of reaction for number of ramets and corms varied with clone and age, indicating the potential for microevolutionary responses to soil nutrient heterogeneity in this population. 5 Phenotypic plasticity increased with plant age; corm and shoot mass were most responsive to nutrient addition, but variation in response among clones was relatively low for these traits. 6 Rhizome mass showed the most variation in plasticity from clone to clone at all plant ages, suggesting that foraging capability could respond to selection pressures such as spatially heterogeneous soil nutrients in this population.

Abstract: BACKGROUND: Saffron is one of the most appreciated and expensive spices known and has been used from the oldest times as a dye for fabrics, a condiment to enrich food and for medicinal purposes. The aim of this study was to evaluate the effect of crop management methods on the quantitative and qualitative characteristics of the spice in southern Italy. Two sowing times (end of July and end of August) and two corm dimensions (4 and 3 cm horizontal diameter) were evaluated. RESULTS: Flowering period and duration were not influenced by the studied factors, while early sowing time and greater corm dimension resulted in a greater number of flowers per m2, increased stigma yield and a greater total yield of replacement corms. Early sowing time also showed a significant positive influence on stigma quality measured as apocarotenoid content according to ISO guidelines. CONCLUSION: The results show that, in a Mediterranean environment, appropriate crop techniques and selection of corms can result in economic levels of production and improve the quantitative and qualitative characteristics of saffron. In fact, according to their apocarotenoid contents, samples from the early (July) and late (August) sowing times belonged to the first and second ISO categories respectively. Copyright © 2008 Society of Chemical Industry