Progress 10/01/13 to 09/30/14
Target Audience: For this reporting period, the project targets scientists working in both the public and private sector in plant breeding and plant pathology of vegetable crops, in particular cucurbit crops and the Capsicums (peppers). Vegetable growers in Puerto Rico and the mainland US are another important target audience, in particular growers of squash/pumpkins and specialty peppers that will be of interest to Hispanic ethnic groups. The project also targets home gardeners in Puerto Rico. Changes/Problems:
What opportunities for training and professional development has the project provided? Five masters-level graduate students and two undergraduate students have been participated in this research during this year. Students have been able to improve their skill in the use of various laboratory equipment, field experimental design, development of survey instruments and data analysis. How have the results been disseminated to communities of interest? Small seed samples of the five experimental lines are available to growers and home gardeners at the Isabela Substation. What do you plan to do during the next reporting period to accomplish the goals?
What was accomplished under these goals?
1. Develop and release improved tropical pumpkin and sweet chili pepper lines, cultivars and germplasm Experimental tropical pumpkin lines were advanced (self-pollinated) another generation (to the F4 or F5). Enough F4 or F5 seed is now available for a replicated field trial. Five experimental lines (G2, G6, G8, G11 and S7) were evaluated in replicated trials at three locations (Mayaguez, Lajas and Isabela). The germplasm was evaluated for plant development over time, fruit yield, fruit size and fruit shape. Fruit from these trials were also used for organoleptic and nutritional characterization as described below. Each line has very distinct phenotypic traits. All five lines appear to merit formal release. The seed of an additional five sweet chili pepper lines introduced from Oregon State University have been increased in order to include this germplasm in future replicated trials. 2. Characterize known resistances in tropical pumpkin germplasm to key viruses of the Potyviridae and use this resistance in cultivar improvement. The primary potyviruses in tropical pumpkin are Papaya ringspot virus (PRSV) and Zucchini yellow mosaic virus (ZYMV). In order to better understand the dynamic of these virus in the field we analyzed data collected from a field survey of 390 cucurbit samples. We observed a strong relationship between these two potyviruses. A total of 66% of samples were positive for PRSV when ZYMV was positive, but only 32% of the samples were positive for PRSV when ZYMV was negative. There was no relationship between habitat (defined as agricultural, rural non-agricultural, and urban) and the relative frequency of PRSV or ZYMV. The absence of virus-like symptoms in the samples collected was not associated with the absence of PRSV or ZYMV infection. 3. Carry out organoleptic and nutritional characterization of current and new tropical pumpkin and sweet chili pepper germplasm. Five experimental lines of sweet chili pepper has been characterized for percentage dry matter, ash, fiber, fat, carbohydrates, protein,total polyphenols, brix, pH, and total acidity in mature fruit samples. In addition, we characterized both immature (green) and mature (orange or red) fruits of each line for color by determining L, chroma and hue angle. Each line was found to have unique combinations of these attributes. To our knowledge, this is the first time sweet chili pepper (non-pungent types of Capsicum chinense), either from Puerto Rico or other areas of the region, has been characterized for these attributes. This information will enable us to more precisely describe the uniqueness of each line when they are formally released. The information also serves as base-line data for other researchers working on peppers. In the case of tropical pumpkin, the local cultivars Soler and Taina Dorada had previously been characterized for dry matter, Brix and color, but we have now also characterized these varieties for pH, percentage acidity, firmness, protein, fat, carbohydrates, ash, and fiber. 4. Develop and test a dried sweet chili pepper value-added product. There have been no accomplishments to date for this goal. 5. Carry out user surveys on purchasing, use and consumption of vegetables, and surveys on acceptance of new sweet chili pepper and pumpkin varieties and products. A survey instrument for sweet chili pepper has been prepared and is being tested and validated. Extension Home Economists in various Puerto Rico municipalities have been contacted and have agreed to make arrangements to recruit participants (primarily housewives) for focal groups. The Puerto Rico Chefs Association has been contacted and we are initiating planning for a "Chefs Field Day" for about 35 chefs from around the island.
Andon-Sanchez, Natasha. 2014. Determinacion de calidad y cambios microbiologicos en calabaza minimalmente procesada y empacada en polietileno de baja densidad ("Determination of quality and microbiological changes in minimally processed pumpkin packed in low density polyethylene bags"). M.S. Thesis. University of Puerto Rico, Mayaguez Campus.
Conference Papers and Presentations
Linares-Ram�rez, A.M. and L. Wessel-Beaver. 2014. Recurrent selection for melonworm resistance in tropical pumpkin. In: (M. Havey, Y. Weng, B. Day, R. Grumet, Editors) Cucurbitaceae 2014 Proceedings, American Society for Horticultural Science, Alexandria, Virginia. Pp. 69-72.