IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Putative self-incompatibility in the rocoto chili (Capsicum pubescens): programic phase and starch mobilization.
Autor/es:
CARRIZO GARCÍA C.
Reunión:
Congreso; 13th Solanaceae Conference. SolGenomics: from advances to applications; 2016
Resumen:
Capsicum pubescens, the so-called ?rocoto?, is a chili pepper native to the highlands of South America, cultivated from Mexico to NW Argentina. As for most Capsicum species, C. pubescens is regarded as self-compatible, but self-incompatible strains have been described in the species and even variable levels of self-incompatibility (SI) have been registered. The occurrence of SI in C. pubescens has been inferred through analyses of the progamic phase and the fruit set. In addition, a relation between pollen reserves and the timing of pollen tube abortion has been proposed as a possible explanation for the differences in the SI level. Because SI alleles could not be retrieved so far in C. pubescens (pers. obs.), a similar approach was followed in a small group of plants cultivated in NW Argentina to analyze the relationship between the level of compatibility, pollen tube growth and starch reserves. Most individuals show some level of SI (fully, mostly, partially SI vs. fully self-compatibility), as evidenced by the fruit set after self- and cross-pollination. Fruit set after cross-pollination is highly variable among plants and does not seem to be related to the level of self-(in)compatibility. Pollen tubes growth was arrested at different lengths along the style when fruit set failed after self-pollination, showing no correlation with the level of self-(in)compatibility or with pollen starch content. Starch content in the stigma/style would not be a constraint that hampers pollen tube development during the progamic phase. Part of the evidence indicates the occurrence of SI in C. pubescens, but many variables have a regulatory role in the relation between pollen tubes and pistil. Starch was considered this time, due to its key participation in pollen tube nutrition, but it does not seem to be a relevant constraint. Further analyses are needed to understand better the irregular behavior of pollen tubes during the progamic phase and the frequent occurrence of not fully SI in C. pubescens, including new attempts at the molecular level.