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  • Author or Editor: Allan K. Stoner x
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The National Plant Germplasm System (NPGS) is responsible for the acquisition, maintenance, evaluation, and distribution of genetic diversity of crop plants important to U.S. agriculture. The NPGS collections currently include more than 425,000 accessions representing more than 8000 species. The curators of the individual active collections face many challenges, including preserving the maximum amount of genetic diversity in active collections, encouraging the use of the germplasm in the collections, and operating with limited resources. During the past 5 years, the NPGS curators and the 40 Germplasm Committees have been evaluating how core subsets can help in meeting these challenges. A set of general guidelines and procedures for developing core subsets has been developed.

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Abstract

Insects inflict over $185 million in losses to vegetables annually in the United States (Table 1). An additional $100 million or more is spent controlling vegetable insects. Totaled the losses and control costs amount to approximately 18% of the value of vegetables grown in the U.S.

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U. S. agriculture has an unmatched record for efficiently producing an abundance of high-quality, modestly priced food. At the 1971 ASHS meeting, and in subsequent articles, Wadleigh eloquently described the impact of agricultural research on the production of vegetables and other horticultural crops since 1920 (35, 36). Scientists of many disciplines have contributed to this success story, but much of the credit goes to plant breeders for the development of improved cultivars.

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Abstract

Tomato plants possessing a high level of resistance to the carmine spider mite, Tetranychus cinnabarinus, can be identified in segregating populations by selecting those with the greatest concentration of glandular hairs on their leaves. The glandular hairs were counted by using a stereoscopic microscope, or estimated with the naked eye when the plants were 8 to 10 weeks old. In 18 of 21 F2 populations studied, plants selected for their high concentration of glandular hairs had higher levels of resistance to mites, as determined by ovi-position rate, than did plants selected for having few hairs. The average number of eggs laid per female mite ranged from 6.2 to 50.5% less on the plants selected for a high concentration of hairs than on those with few hairs. Selection with the naked eye was as effective in identifying resistant segregates as was actual glandular hair counts.

Open Access

The United States' National Plant Germplasm System (NPGS) is responsible for the acquisition, preservation, evaluation and distribution of plant genetic resources in the form of seed and clonal germplasm. In order to operate more effectively, the NPGS established a network of 40 Crop Advisory Committees (CACs) to provide analysis, data, and advice about germplasm within a crop or group of related crops of current or future economic importance. CACs are composed of Federal, State and industry scientists representing a variety of agricultural disciplines and geographic areas of importance to the crop. The committees are involved in a variety of activities including: 1) Developing crop descriptors for the collection of standardized characteristic and evaluation data, 2) Determining priorities for germplasm acquisition, evaluation and enhancement, 3) Advising curators on maintenance techniques, and 4) Developing special reports on the status of genetic resources for their crop(s). Twenty-four of the CACs are concerned with horticultural crops.

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Abstract

A screening method is proposed to select for high temperature fruit setting ability in the tomato (Lycopersicon esculentum, Mill) on the basis of fruit set under high summer temperature in the greenhouse.

Open Access

Abstract

First generation of larvae of the Colorado potato beetle (Leptinotarsa decemlineata (Say)) were primarily responsible for a 67% reduction in yield of tomato (Lycopersicon ‘esculentum Mill.) when their numbers increased from 5 to 10 per plant.

Open Access

Abstract

Abscisic acid (ABA) levels in seeds of tomato (Lycopersicon esculentum Mill.) fell about 10-fold during fermentation to remove mucilaginous tissue. Imbibing seeds in 20 µg/ml ABA prevented germination and increased ABA content of the seed 15-fold. Subsequent germination in water averaged greater than 90%.

Open Access

Abstract

A critically important aspect of the management of genetic resources is concurrent management of information pertinent to the preserved seeds or plant materials. An effective information system should: a) aid curators of collections by providing current information on inventories, exchange activities, etc.; b) perm it germplasm users to have rapid access to botanical and horticultural information about specific accessions and thereby encourage more effective use of plant germplasm; and c) allow personnel and organizations within and between countries to coordinate activities related to germplasm collection, exchange, and maintenance.

Open Access

Abstract

Drosophila, or the vinegar fly as it is commonly called, is one of the most serious insect pests with which the processor of tomatoes has to contend today. It is primarily an insect contamination or nuisance problem. Tomato products found to be contaminated with any stage of this insect are subject to seizure and condemnation. Of the several species of Drosophila that may infest tomatoes, D. melanogaster Meigen is normally the most serious.

Open Access