Tea Germplasm and Breeding in China

Abstract

The tea plant is native to China, which was firstly found and made use of as a beverage thousands of years ago. The country has the greatest tea production and consumption in the world, especially green tea and Oolong tea. In 2009, China had 1,866.7 kilohectares of tea gardens and 1,344.4 kilotonnes of tea annual production. China has abundant tea genetic resources capable of providing diverse parent materials for tea breeding. Currently, it is estimated that more than 3,000 accessions have been collected and conserved in the national germplasm tea repository. Different methods, which included ex-situ, in-situ and in vitro, were employed to prevent the loss of tea germplasm and ensure the preservation of genetic diversity. The tea germplasms have been evaluated and appraised based on morphology, physiology, agronomy, cytology and molecular biology, through which the elite and unique tea accessions were screened and further utilized in tea breeding. Recently, the appraisal and evaluation of tea germplasms was further regulated and standardized to boost efficiency and informative management. An efficient tea breeding system, in which controlled hybridization and individual selection are the main breeding approaches, combined with molecular marker-assisted selection and micropropagation techniques, has now been established and gradually developed in China. Up to date, a total of 123 cultivars have been registered as national tea cultivars. More than 150 cultivars have been accredited for release in given provinces and 4 clones have been covered by Plant Varieties Protection (PVP) in China. A standardized tea cultivar propagation and extension system has been established and is being implemented in China. This chapter reviewed the current situation of collection, conservation, appraisal and evaluation of tea germplasms, the achievements of tea genetic improvement and breeding, and the establishment and development of tea breeding as well as extension systems. Finally, suggestions were made on possible areas of research emphasis for the genetic improvement of the tea plant in the near future in China.