Study of the influence of pollination on the number of seeds in mandarin IAC 2019Maria

• Grant number: 18/02694-3
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): May 01, 2018
• Effective date (End): December 31, 2019
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal researcher: Mariângela Cristofani-Yaly
• Grantee: Fernanda Roverssi
• Home Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

In the State of São Paulo, the main national citrus producer, the following varieties of the tangerines and their hybrids stand out as the most cultivated: Ponkan tangerine (Citrus reticulata Blanco) and Murcott tangor [Citrus sinensis (L.) Osbeck x C. reticulata Blanco]. Other varieties, such as Rio willowleaf (C. deliciosa Tenore) and Cravo tangerine, have little expression in relation to the planting area. These varieties do not meet the international acceptance standard, to be consumed as fresh fruit, because the market highly values the seedless fruits. In addition, these varieties are highly susceptible to the brown spot of alternaria (BSA), a disease caused by the fungus Alternaria alternata, being considered the most severe fungal disease today, attacking the tangerines and some of its hybrids. The disease severely affects orchards grown with the Ponkan and Murcott tangor varieties, the main varieties grown in Brazil, causing economic losses to commercial orchards due to the large number of sprays required for control. In the Citrus Breeding Program of the Citrus Center Sylvio Moreira of the Agronomic Institute (IAC) a cultivar, IAC 2019Maria, which has been highly resistant to this disease was developed. The cultivar, although presenting less seeds than Ponkan tangerine and Murcott tangor, presents on average ten seeds per fruit. The plants of the cultivar IAC 2019Maria mandarin have always been cultivated in the presence of other varieties. In this way, we do not have the knowledge of the viability of the pollen, of occurrence or not of autoincompatibility and influence of cross-pollination in the number of seeds. This preliminary study will allow to verify the influence of open pollination, self pollination and the absence of open pollination and self pollination in the seed formation, in fruits of the tangerine cultivar IAC 2019Maria and if the reduction in the number of seeds will have consequences in the quality of the fruit. (AU)