Abstract: New tomato varieties were selected and bred for protected cultivation. Zhongza 8 and Zhongza 9 were developed on the basis of combination of wide cross and gene combination. Firstly, some hybrid tomato seeds were introduced from US, the Netherlands and Japan. And then several elite inbred lines including 892-43,882-32,892-54,882-7 were screened by self-cross segregation combined with cross breeding, artificial inoculation and combining ability tests in the protected field. Among them, two hybrid combinations 892-43× 892-54 and 882-32×882-7 performed excellent in repeated trials, regional tests and production tests, and they were nominated as Zhongza 8 and Zhongza 9 respectively. Zhongza 8 and Zhongza 9, possessed several characteristics: (1) strong multiple resistance: high resistance to TOMV, mid-resistance to CMV, leaf mould and fusarium wilt; (2) tolerance to low temperature and weak light; (3)high fruit quality, high marketable percentage and resistance to cracking; (4) high yield. Zhongza 8 and Zhongza 9 are new varieties for protected cultivation. They contain cf5 gene and are highly resistant to ToMV and mid-resistant to CMV and Fusarium wilt.

Key words: Lycopersicon esculentum , Breeding , Disease resistance , Qulity , Zhongza 8 , Zhongza 9