Germplasm Collections

A wide range of germplasm resources are available for breeding and research on tomato (see recent reviews

Table 2. World production of tomatoes in 1995 and 2004 (FAOSTAT 2004)

Location

1995

2004

Area

Yield

Production

Area

Yield

Production

(ha x 103)

(ton ha-1)

(ton x 103)

(ha x 103)

(ton ha-1)

(ton x 103)

World

3,286

26.7

87,722

4,530

27.5

124,422

Africa

505

20

10,090

703

20

12,428

North and

359

42.7

15,341

333

52.8

15,838

Central America

South America

156

37

5,769

147

43.4

6,481

Asia

1,538

23.9

36,778

2,655

23.8

53,290

Europe

716

26.9

19,264

682

29.8

19,969

Oceania

12

39.3

481

10

50

492

Leading Countries

China

474

27.8

13,172

1,255

24

30,144

USA

192

61.3

11,784

175

73.7

12,867

Turkey

175

41.4

7,250

255

37

9,440

India

350

15

5,260

540

14.1

7,600

Egypt

149

33.7

5,034

195

39.2

7,640

Italy

114

45.1

5,182

145

53

7,682

by Chetelat and Ji 2007; Ji and Scott 2007; Robertson and Labate 2007). Tomato germplasm collections in the USA are currently maintained at two major genebanks, the C.M. Rick Tomato Genetics Resources Center (TGRC), at the University of California - Davis, and the United States Department of Agriculture, Agricultural Research Service (USDA-ARS) Plant Genetic Resources Unit (PGRU) in Geneva, NY. The former consist mainly of wild species, mutants, prebreds, and other types of genetic stocks (Table 4), the latter emphasizes open-pollinated cultivars and some wild relatives. In addition, the Seed Savers Exchange in Decorah, Iowa, maintains a large set of heirloom and antique varieties through its network of growers. The major international collection of tomato germplasm is preserved at the Asian Vegetable Research and Development Center (AVRDC), now referred to as The World Vegetable Center, located at Taiwan. Other significant collections are housed in The Netherlands, Germany, France, and Russia. Worldwide, over 75,000 accessions of Solanum sect. Lycopersicon germplasm are maintained in more than 120 countries in a number of national institutions; for detail see review by Robertson and Labate (2007).

Germplasm collections in these genebanks have been intensively utilized as genetic resources for many types of basic and applied research involving tomato (Rick and Chetelat 1995; Ji and Scott 2007). Uses include searching the collections for traits of economic interest, such as disease and insect resistances, stress tolerances, and improved horticultural and fruit characteristics. Research topics of more fundamental nature include studies in physiology and development (e.g., leaf development, fruit ripening and self-incompatibility), genetics (e.g., wide hybridization, linkage and QTL mapping), and genomics (e.g., map-based cloning and comparative sequence analysis).

Was this article helpful?

0 0

Post a comment