Chowdhary Kanika, Kaushik Nutan
TERI University, 10th Institutional Area, Vasant Kunj, New Delhi, India.
The Energy and Resources Institute (TERI), India Habitat Center, Lodhi Road, New Delhi, India.
PLoS One. 2015 Nov 3;10(11):e0141444. doi: 10.1371/journal.pone.0141444. eCollection 2015.
Endophytic mycopopulation isolated from India's Queen of herbs Tulsi (Ocimum sanctum) were explored and investigated for their diversity and antiphytopathogenic activity against widespread plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani and Fusarium oxysporum. 90 fungal isolates, representing 17 genera were recovered from 313 disease-free and surface sterilised plant segments (leaf and stem tissues) from three different geographic locations (Delhi, Hyderabad and Mukteshwar) during distinct sampling times in consequent years 2010 and 2011 in India. Fungal endophytes were subjected to molecular identification based on rDNA ITS sequence analysis. Plant pathogens such as F. verticillioides, B. maydis, C. coarctatum, R. bataticola, Hypoxylon sp., Diaporthe phaseolorum, Alternaria tenuissima and A. alternata have occurred as endophyte only during second sampling (second sampling in 2011) in the present study. Bi-plot generated by principal component analysis suggested tissue specificity of certain fungal endophytes. Dendrogram revealed species abundance as a function of mean temperature of the location at the time of sampling. Shannon diversity in the first collection is highest in Hyderabad leaf tissues (H' = 1.907) whereas in second collection it was highest from leaf tissues of Delhi (H' = 1.846). Mukteshwar (altitude: 7500 feet) reported least isolation rate in second collection. Nearly 23% of the total fungal isolates were considered as potent biocontrol agent. Hexane extract of M. phaseolina recovered from Hyderabad in first collection demonstrated highest activity against S. sclerotiorum with IC50 value of 0.38 mg/ml. Additionally, its components 2H-pyran-2-one, 5,6-dihydro-6-pentyl and palmitic acid, methyl ester as reported by GC-MS Chromatogram upon evaluation for their antiphytopathogenic activity exhibited IC50 value of 1.002 and 0.662 against respectively S. sclerotiorum indicating their significant role in antiphytopathogenic activity of hexane extract. The production of 2H-pyran-2-one, 5,6-dihydro-6-pentyl from M. phaseolina, an endophytic fungus is being reported for the first time.
对从印度的药草之王罗勒（神圣罗勒）中分离出的内生真菌种群进行了探索和研究，以了解其多样性以及对广泛存在的植物病原体灰葡萄孢、核盘菌、立枯丝核菌和尖孢镰刀菌的抗植物病原活性。在2010年和2011年印度不同的采样时间，从三个不同地理位置（德里、海得拉巴和穆克台什瓦尔）的313个无病且经过表面消毒的植物片段（叶和茎组织）中分离出90株真菌菌株，代表17个属。基于核糖体DNA ITS序列分析对真菌内生菌进行分子鉴定。在本研究中，诸如轮枝镰孢、玉米大斑病菌、窄孢炭疽菌、菜豆根腐病菌、炭团菌属、菜豆间座壳、细极链格孢和链格孢等植物病原体仅在第二次采样（2011年第二次采样）时以内生菌的形式出现。主成分分析生成的双标图表明某些真菌内生菌具有组织特异性。聚类图显示物种丰度是采样时所在位置平均温度的函数。第一次采集时，海得拉巴叶组织中的香农多样性最高（H' = 1.907），而在第二次采集时，德里叶组织中的香农多样性最高（H' = 1.846）。穆克台什瓦尔（海拔：7500英尺）在第二次采集时的分离率最低。近23%的真菌分离株被认为是有效的生物防治剂。第一次采集时从海得拉巴分离出的菜豆壳球孢的己烷提取物对核盘菌表现出最高活性，IC50值为0.38毫克/毫升。此外，气相色谱 - 质谱联用色谱图报告的其成分2H - 吡喃 - 2 - 酮、5,6 - 二氢 - 6 - 戊基和棕榈酸甲酯在评估其抗植物病原活性时，对核盘菌的IC50值分别为1.002和0.662，表明它们在己烷提取物的抗植物病原活性中起重要作用。首次报道了内生真菌菜豆壳球孢产生2H - 吡喃 - 2 - 酮、5,6 - 二氢 - 6 - 戊基。
