The process of self-incompatibility in Citrus is a critical mechanism for producing seedless fruit of high commercial value. The project aims to understand how temperature stress alters the self-incompatibility complex and to assess the detrimental effects of cold and heat stress during reproduction.

The project includes application of stress conditions to compatible and incompatible varieties, histo-molecular analysis of reproductive organs and fertilization process. It will also study damage to molecular processes of SI response caused by temperature stress on male and female gametophytes.

The data will be evaluated within the expected variation in gene expression assessed by transcriptomic and epigenetic analyses. The project is divided into the following work packages:

WP1. Monitoring the reproductive biology of selected varieties of mandarins and mandarins-like (clementine) under different temperature conditions

WP2 - In vitro evaluation of the effects of temperature change on pollen of selected varieties to identify impaired molecules/processes that affect the incompatibility reaction and pollen tube growth

WP3. Analysis of female gametophyte in stressed plants: does temperature stress affect the development of ovules and the receptivity/signaling/guidance of pistils?

WP4. Omics approach for the evaluation of male and female gametophytes’ formation and progamic phases under controlled stress conditions for selected mandarin varieties

Diagram of the reproductive process showing the effect of heat/cold stress on self-incompatibility and the specific target of each WP:

Citrus flowers will be subjected to stress temperatures (heat, cold stress) and then the reproductive performance and the incompatibility response will be evaluated according to the four work packages (WP) described. M: male gene/protein determinant; F: female gene/protein determinant.