Past Research – Page 5

2005 Abhaya M. Dandekar (Improving Peel Quality of California Citrus Fruit)

Improving Peel Quality of California Citrus Fruit

High quality peels are a critical component of high value fresh market citrus fruit. Peel quality is defined by the expression of specific gene sets during development that result in the development of the external finish of fresh fruit, a genetic phenotype that is a key factor for marketing of the product. Our study has two specific objectives: (1) To survey the pattern of genes expressed in peel tissues that determine quality of citrus fruit, and (2) To identify and validate genes associated with the development of fruit quality and peel related external finish disorders.

2005 Eduardo Blumwald (Physiological and Biochemical Determinants of Sugar and Acid)

Physiological and Biochemical Determinants of Sugar and Acid Content in Citrus Fruits and Citrus Fruit Proteomics.

Citrus fruit quality standards have been determined empirically, depending on species and on the particular growing regions. In general, the TSS (total soluble solids) to total acidity (TA) ratio determines whether citrus fruit can be marketed.

2005 Henry J. Fisk (Development of Citrus Cultivars with Reduced Juvenility)

Development of Citrus Cultivars with Reduced Juvenility

The overall objective of this project has been to develop technology that will allow for the creation of commercially important citrus species that have reduced juvenility. Since most citrus improvement programs involve the use of seedlings, plants with reduced juvenility will prove invaluable for expediting work that is based in conventional breeding, biotechnology, or a combination of the two due to a shorter time period required for screening, evaluations and/or subsequent crosses.

2005 Fisk/Dandekar (Genetic engineering of Citrus)

Genetic Engineering of Citrus

The main goal of this work has been to develop genetic transformation methods for citrus scion cultivars important to the California industry. The cultivars investigated during the 2004-05 funding cycle included Washington navel and Valencia sweet oranges, Kinnow and Owari Satsuma mandarins, Eureka lemon and Mexican lime. Additional varieties, particularly mandarins, have been considered for future experiments.

2005 Wright/Kahn/Mauk (Evaluation of Lemon Selections for the Desert)

Evaluation of Lemon Selections for the Desert

For more than 75 years, California has been a leader in the worldwide fresh lemon industry. To maintain and increase its market share, steps that the industry must take include developing high quality lemon varieties that are adaptable to the diverse California climates, meet the demands of the marketplace, and produce acceptable returns for the grower.

2005 Mary Lu Arpaia (Harvest and Evaluation of Strain Trials at Lindcove)

Harvest and Evaluation of Strain Trials at Lindcove Research and Extension Center

Our progress on the two portions of this study is outlined below, plus a near-final summary of the Valencia strain portion of the project which was terminated in 2003.

2005 Mikeal L. Roose (Breeding of New Citrus Scion Varieties)

Breeding of New Citrus Scion Varieties

The objectives of this project are to develop new mandarin, orange, lemon and grapefruit cultivars suitable for California conditions. Developing new varieties is a long-term project that has been funded by the CRB since 1994.

2005 Tracy L. Kahn (Citrus Variety Evaluation for Trueness-To-Type)

Citrus Variety Evaluation for Trueness-to-Type and Commercial Potential

High quality citrus varieties which are adapted to California climates and meet market needs are crucial to the industry to maintain competitiveness in the global and domestic fresh citrus markets. To be responsive to market changes such as the increasing market desire for seedless tangerines, our project continues to provide the industry with preliminary information on the characteristics of citrus varieties in California, to evaluate trueness-to-type of varieties distributed by the Citrus Clonal Protection Program, and to maintain the citrus evaluation blocks to serve as demonstration material for tours, fruit displays and periodic field days for California growers.

2005 Mikeal L. Roose ( Citrus Rootstock Breeding and Evaluation)

Citrus Rootstock Breeding and Evaluation

The general objectives of this project are to develop, test and evaluate citrus rootstocks for disease and pest tolerance, and to select stocks which impart to the scion high yield, superior fruit quality, acceptable fruit size, and other essential traits. This is a long-term project that has been supported by the CRB since 1982.

2005 Robert R. Krueger (Seasonal Variations in N Uptake & Nutrient Concentrations in Mature Field-Grown Citrus)

Seasonal Variations in N Uptake and Nutrient Concentrations in Mature Field-Grown Citrus

Final Report
This constitutes the final report for this project. A few data points are missing due to delays in isotopic analysis, however estimates have been made for the missing points as referenced below. The objectives of this study were to measure seasonal variations in mineral nutrient concentration and mass in vegetative organs and fruit of mature citrus trees, to estimate seasonal variations in nitrogen uptake, and to estimate the amount of nitrogen removed from soil.