玉米种质和新品种对腐霉茎腐病和镰孢穗腐病的抗性分析

Analysis of Maize Accessions Resistance to Pythium Stalk Rot and Fusarium Ear Rot

玉米是我国最重要的农作物之一,腐霉茎腐病和镰孢穗腐病是玉米生产上的重要病害。2006-2012年期间,对1647份玉米种质进行了抗肿囊腐霉茎腐病和拟轮枝镰孢穗腐病鉴定,筛选出高抗茎腐病和穗腐病的种质分别为564份和27份,占鉴定总材料的34.2%和1.6%,抗性材料分别为209份和352份,占比为12.7%和21.4%,表明高抗肿囊腐霉茎腐病的资源较为丰富,高抗镰孢穗腐病的种质相对匮乏。其中,13份种质对2种病害均表现高抗,207份种质对2种病害均表现抗性或对其中一种表现高抗而另一种表现抗性。自交系中对肿囊腐霉茎腐病和拟轮枝镰孢穗腐病表现抗性以上(含HR和R)的种质分别占总鉴定种质的56.5%和23.6%,在农家种中分别为21.2%和21.4%,表明玉米自交系中的抗性资源较农家种丰富。2009-2013年期间参加国家玉米区试的品种中,对腐霉茎腐病表现高抗、抗性、中抗、感病和高感的品种分别占11.5%、11.9%、40.1%、17.6%和18.9%。2009-2011年间,中抗以上的育成品种所占比例呈现明显上升趋势,但2012-2013年间,中抗以上的品种所占比例呈下降趋势。

Maize is one of the most important crops in China. Pythium stalk rot and Fusarium ear rot are serious diseases in maize production. A total of 1647 maize accessions were screened for resistance to these two diseases from 2006 to 2012. 564 and 27 germplasm was highly resistant to Pythium stalk rot and Fusarium ear rot, accounting for 34.2% and 1.6% of total accessions screened, respectively. In addition,209 and 352 accessions with resistance to Pythium stalk rot and Fusarium ear rot were discovered, accounting for 12.7% and 21.4% of total accessions, re- spectively. Among resistant germplasm, there were 13 accessions with high resistance to two diseases and 207 acces- sions with resistance to two diseases or resistance to one and high resistance to another. In present study,56.5% and 23.6% of maize inbred lines were highly resistant or resistant to Pythium stalk rot and Fusarium ear rot, whereas 21.2% and 21.4% of germplasm in landraces were resistant to these two diseases, respectively, indicating higher level of resistance and more multiple resistance in inbred lines than in ]andraces. Among 227 corn varieties partici- pating in national regional test in 2009 - 2012,11.5%, 11.9% ,40. 1%, 17.6% and 18.9% of varieties were highly resistant, resistant, moderately resistant, susceptible and highly susceptible to Pythium stalk rot, respectively.The total of ratio of new varieties with moderate resistance, resistance and high resistance obviously tended to ascend during 2009 - 2011, but descended in 2012 - 2013.