Cao Shifeng, Zheng Yonghua, Tang Shuangshuang, Wang Kaituo
College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Int J Food Microbiol. 2008 Aug 15;126(1-2):216-20. doi: 10.1016/j.ijfoodmicro.2008.05.026. Epub 2008 May 27.
The beneficial effect of 2% CaCl(2) (w/v) on the antagonistic yeast Pichia membranifaciens for control of anthracnose rot caused by Colletotrichum acutatum in postharvest loquat fruit (Eriobotrya japonica L.) and the possible mechanisms involved were investigated. The results showed that treatment with P. membranifaciens at 1x10(8) CFU ml(-1) or 2% CaCl(2) alone both resulted in significantly smaller lesion diameter and lower disease incidence of anthracnose rot on loquat fruit wounds compared with the controls. The biocontrol activity of P. membranifaciens on the disease was enhanced by the addition of 2% CaCl(2), the combined treatment of P. membranifaciens with CaCl(2) resulted in a remarkably improved control of the disease in comparison with the treatment of P. membranifaciens or CaCl(2) alone. P. membranifaciens in combination with CaCl(2) induced higher activities of two defense-related enzymes chitinase and beta-1,3-glucanase in loquat fruit than applying the yeast or CaCl(2) alone. The in vitro experiment showed that the addition of 2% CaCl(2) in the suspensions of P. membranifaciens significantly inhibited spore germination and germ tube elongation of C. acutatum than the yeast or CaCl(2) alone. However, adding CaCl(2) did not significantly influence the population of P. membranifaciens in NYDB medium or fruit wounds. These results suggest that CaCl(2) could improve the biocontrol activity of P. membranifaciens on anthracnose rot in loquat fruit. It is postulated that the improved control of the disease is directly because of the higher inhibitory effect on pathogen growth and indirectly because of the enhanced disease resistance in loquat fruit by the combination treatment.
研究了2%氯化钙（w/v）对拮抗酵母膜醭毕赤酵母控制采后枇杷果实（Eriobotrya japonica L.）由尖孢炭疽菌引起的炭疽病腐烂的有益作用及可能涉及的机制。结果表明，与对照相比，用1×10⁸ CFU ml⁻¹的膜醭毕赤酵母或单独使用2%氯化钙处理均导致枇杷果实伤口上炭疽病腐烂的病斑直径显著更小且发病率更低。添加2%氯化钙增强了膜醭毕赤酵母对该病的生物防治活性，与单独使用膜醭毕赤酵母或氯化钙处理相比，膜醭毕赤酵母与氯化钙联合处理对该病的防治效果显著提高。与单独施用酵母或氯化钙相比，膜醭毕赤酵母与氯化钙联合处理诱导枇杷果实中两种防御相关酶几丁质酶和β-1,3-葡聚糖酶的活性更高。体外实验表明，在膜醭毕赤酵母悬浮液中添加2%氯化钙比单独使用酵母或氯化钙显著抑制尖孢炭疽菌的孢子萌发和芽管伸长。然而，添加氯化钙对NYDB培养基或果实伤口中膜醭毕赤酵母的数量没有显著影响。这些结果表明，氯化钙可以提高膜醭毕赤酵母对枇杷果实炭疽病腐烂的生物防治活性。据推测，对该病防治效果的提高直接是由于对病原菌生长的抑制作用更强，间接是由于联合处理增强了枇杷果实的抗病性。
