Breeding Of Hybrid Cotton "Chuangza 21" With Pests Resistance

Since the late 1980s,Bt genes have been transconducted into cells of different plant tissue in many experiments,and the expressin have been detected in plant cells wich has been transformed.It has been proven that the engineering genetic characteristics are stable, which has been transconducted into progencies in Mendelian genetics.This paper utilized GK19,the national approved variety,as the provider of Bt genes,to cross with Chan-A2 in 1998.Than the tranditional breeding method wsa used to plant selecton,identification for many generations.The new line 544 with Bt genes was breeded in the year of2001.Another high yield line 536 was selected from the cross of 138×3247 using the same method.The combination between 536×544(labed Chuangza 21 Hao) was tested in the field from 2002-2004,indicating outstanding yield and acceptable fibrer qualities.From 2005 to 2006,"Chuangza 21" attended national cotton evaluation experiment of Changjiang region.The average seed cotton yield,lint yield and lint yield before Oct.30, were above the check variety(Xiangzamian 8) 7.4%,11.5%,13.0%respectly.Chuang Za 21was identified to resist cotton Fusarium wilt and tolerate Verticillium Wilt.It was middie-resistance to boll worm and resistance to pink boll worm.The main fiber quality parameters of Chuang Za 21 were:length 29.6 mm,strenth 27.9cN/tex,Micnare 5.2。Chuang Za 21 is now attending the production test in 2007,and probably get approved in 2008.The breeding of "Chuangza 21",with high yield and pests resistance can supply one more choice for farmers in cotton production,and benefit the reduction of environmental pollution.