爵床提取物对辣椒炭疽病菌的抑制作用及其苗期防效

Inhibition of the extracts from Justicia procumbens against Colletotrichum gloeosporioides and its efficacy at the seedling stage

爵床(Justicia procumbens L.)是一种传统的中药材。为探明爵床提取物对辣椒炭疽病菌的抑制作用,采用生长速率法和孢子萌发法分别测定了爵床提取物对辣椒炭疽病菌菌丝生长、孢子产生和孢子萌发的抑制作用,采用苗期盆栽试验观察爵床提取物对辣椒炭疽病的防治效果。结果表明,爵床甲醇提取物可抑制辣椒炭疽病菌菌丝生长、孢子产生和孢子萌发,其活性随着浓度的提高而增强,抑制中浓度分别为4.23、2.16和2.98mg/mL。通过对爵床提取物处理后病菌孢子萌发形态显微观察,发现病菌孢子芽管长度受到明显抑制甚至不能萌发。当提取物浓度为16mg/mL时对苗期辣椒炭疽病的防效达73.08%。

Justicia procumbens is a kind of traditional Chinese medicine. In order to ascertain the fungicidal activity of the extracts from J. procumbens, the inhibitory effects of the extracts from J. procumbens against mycelial growth, co nidial production and conidial germination of Colletotrichum gloeosporioides were assayed by the methods of mycelial growth rate and conidial germination, and the efficacy of the extracts from J. procumbens was tested against C. gloeospo rioides by pot culture experiments at pepper seedling stage. The results showed that methanol extracts from J. procumbens had inhibitory effects against mycelial growth, conidial production and conidial germination of C. gloeosporioides, and its values of effective concentration （EC50） were 4.23, 2.16 mg/mL and 2.98 mg/mL, respectively. The germ tube length of C. gloeosporioides conidia was obviously inhibited, and even conidia could not germinate by the observa tion of microscope after treated with the extracts. Its efficacy was 73.08% after sprayed against C. gloeosporioides at the concentration of 16 mg/mL at pepper seedling stage.