The endophytic capacity of Beauveria bassiana Vuillemin isolates in 2 tomato varieties and their effects on damage and survival of the tomato fruit worm Helicoverpa armigera Hubner larvae were studied. The bioassays consisted of sowing seeds of 2 tomato cultivars soaked for 24 h in B. bassiana conidial suspension at the concentration of 1 × 107 and 1 × 109 conidia/ml for the isolates Bb 115 and Bb 11, respectively. Ten leaf, stem, and root segments were cut and incubated for assessing the endophytic growth of the fungus. Percentage of leaf consumption and pathogenicity of B. bassiana on H. armigera larvae were estimated. The fungus B. bassiana developed endophytically in the 2 tomato varieties and was detected in tomato leaf, stem, and root. However, higher colonization rates were observed in roots than in leaves and stems. The B. bassiana isolate Bb 115 had a greater negative effect on the mean survival times (MSTs) of H. armigera larvae and on leaf consumption for local and improved tomato varieties. In fact, the lowest MSTs were recorded at the concentration of 1 × 109conidia/ml for Bb 115 in 1.5 ± 0.2 days, i.e., 7 days less than the surviving larvae of the control group, which MSTs were 8.4 ± 0.9 days. Consumed leaf areas by larvae averaged (89.17 ± 10.33 mm2) at a fungal concentration of 1 × 109conidia/ml for Bb115. It was the best compared to that of untreated control (820.3 ± 92.77 mm2). The colonization rate of the different plant parts increased with conidia concentration in both tomatoes varieties. This study reported the effect of endophytic colonization of tomato by B. bassiana on the survival of H. armigera larvae and showed that the isolates Bb 115 and Bb 11 could be considered as useful microorganisms for the integrated control of H. armigera.

中文翻译：

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球孢白僵菌（Beauveria bassiana Vuillemin）（子囊菌：Hypocreales）对番茄植物的内生定植和棉铃虫（Hübner）（鳞翅目：夜蛾科）幼虫的叶片损伤

研究了两个番茄品种中球孢白僵菌分离物的内生能力及其对番茄果蝇Helicoverpa armigera Hubner幼虫的伤害和存活的影响。生物测定法包括将两个番茄品种的种子分别在分离的Bb 115和Bb 11中以1×107和1×109分生孢子/ ml的浓度在B. bassiana分生孢子悬液中浸泡24 h。切下十个叶，茎和根段，并孵育以评估真菌的内生生长。估计了叶片消费量的百分比和球孢杆菌对棉铃虫幼虫的致病性。球孢白僵菌在两个番茄变种中内生发育，并在番茄的叶，茎和根中被检测到。然而，在根部观察到比在叶和茎中更高的定植率。B. 球茎鲈分离物Bb 115对棉铃虫幼虫的平均存活时间（MST）以及当地和改良番茄品种的叶片消耗具有更大的负面影响。实际上，在1.5±0.2天之内，Bb 115的最低MSTs记录为1×109分生孢子/ ml，即比对照组的存活幼虫（8.4±0.9天）少7天。Bb115的真菌浓度为1×109分生孢子/ ml时，幼虫消耗的叶片面积平均（89.17±10.33 mm2）。与未处理的对照（820.3±92.77 mm2）相比，它是最好的。在两个番茄品种中，不同植物部位的定殖率均随分生孢子浓度的增加而增加。该研究报道了球孢杆菌对番茄的内生菌落定殖对H.存活的影响。