Comparative and functional genome of citrus

• Grant number: 00/10161-1
• Support Opportunities: Genome Research Grants
• Start date: October 01, 2000
• End date: April 30, 2006
• Field of knowledge: Agronomical Sciences - Agronomy
• Principal Investigator: Marcos Antonio Machado
• Grantee: Marcos Antonio Machado
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil
• Associated scholarship(s): 03/00732-0 - Agronomical & environmental genome - AEG, BP.TT; 01/04507-5 - Agronomical and Environmental Genomes, BP.TT

Abstract

Citrus species and related genus as Poncirus have chromosome basic number of x=s, being diploid (2n=2x=18) The genome size (C value) is 0,6 pg per haploid DNA content, or equivalent to 5,63 x 105 kb of DNA. Botanical and genetical traits are the main hindrances to improve genetic gains in breeding programs of citrus species. Potential cultivars need several years, normally over 25 years, to be evaluated before released. The limited number of commercial varieties used in Sao Paulo points out the narrow genetic base of the Brazilian citrus industry, and accounts for its low productivity. Among the factors that contribute with the low productivity are diseases and pests, whose control accounts for the greatest part of the resources spent in an orchard. This proposal intend to perform an extensive comparison of total of 82,000 ESTs of sweet orange, mandarin and P. trifoliata emphasizing important differences that could be correlated to tolerance and susceptibility to diseases (CVC, citrus canker, and gummosis), juvenile and adult phases, and fruit quality. Data will be used for genome comparison, studies on gene expression, genetic mapping of true species and their hybrids. The information will be important in the evaluation and production of new varieties with high tolerance to limiting diseases and with better fruit quality. (AU)