Soil salinity is one of the major obstacles that is limiting the growth and yield of groundnut. This study aims to investigate the effect of growth-promoting fungi, Trichoderma, on groundnut plants that were cultivated in saline conditions. Five different Trichoderma isolates were grown in four different NaCl concentrations. Selected Trichoderma were then applied to the groundnut seeds and their growth and development were monitored during the study. Growth inhibition, volatile organic compounds, chlorophylls, carotenoids, total phenolics and flavonoids, and minerals were assessed between the Trichoderma treatments. Increasing the salt concentration from 0.25–0.75 M decreased the growth of the Trichoderma isolates. The amounts and profiles of the volatile organic compounds from the T. asperellum isolate were significantly different to those in the T. virens isolate. In the vegetative growth stage, increased chlorophyll content was recorded in both the T. asperellum and T. virens-treated groundnut. The leaves that were obtained from the groundnut that was treated with T. virens T.v4 contained significantly higher indole-3-acetic acid (420 µg IAA/g) than the same plants’ roots (113.3 µg IAA/g). Compared to the control groundnut, the T. asperellum T.a8-treated groundnut showed increased phenolics (31%) and flavonoids (43%) and increased shoots and biomass weight at the generative growth stage. This study demonstrates that Trichoderma, with their plant growth promotion ability, could potentially be used to improve the growth of groundnut growing under salinity stress. Importantly, salt-tolerant Trichoderma could be regarded as a beneficial and sustainable way to improve the survival of salt-sensitive crops.

Inayati A, Sulistyowati L, Aini LQ, Yusnawan E. 2020. Trichoderma virens-Tv4 enhances growth promoter and plant defense-related enzymes of mungbean (Vigna radiata) against soil-borne pathogen Rhizoctonia solani. Biodiversitas 21: 2410-2419. Trichoderma virens has been studied for its ability to control various soil-borne pathogens as well as to induce plant resistance. The ability of T. virens control R. solani and its capability to induce resistance was evaluated in two different genotypes of mungbean (Vigna radiata (L.) R. Wilczek). Plant growth-promoting capability and production of plant defense-related enzymes during plant-pathogen-Trichoderma interaction were investigated. Pathogen infection caused the morphological and biochemical changes as well as increased plant defense enzymes activity such as peroxidase, polyphenol oxidase, PAL, phenolics, and flavonoid compared to control uninoculated plants. T. virens improved mungbean seedling growth in terms of increased total biomass, root weight, and root length as well as improved chlorophyll content and IAA-synthase from leaves and roots. T. virens treatment alone or in the presence of pathogen-induced mungbean defense-related enzymes indicated by the increasing of PO and PPO activity, and higher accumulation of total phenolic and flavonoid content. Although most of plant induced resistance parameters showed low and non-significant in direct single-factor comparison, Pearson’s correlation showed there was a positive correlation between plant growth promoter compounds (IAA and chlorophyll) with plant defense-related enzymes (total phenol, and flavonoid content). T. virens treatment can induce systemic defense response of mungbean seedling directly by increasing the activity of some defense-related enzymes, and indirectly by improving plant health, and promoting plant growth. In conclusion, T. virens-Tv4 has potential to be developed as bio-control agents to control R. solani as well as to induce mungbean resistance.

Soybean rust caused by Phakopsora pachyrhizi is one of the most important diseases which limits soybean production. The aim of this study was to evaluate the resistance of 28 superior soybean lines and their tolerance to rust. The study was conducted at a screen house and arranged in a completely randomized design (CRD); three replications. All genotypes tested were artificially inoculated with P. pachyrhizi, and a set of un-inoculated genotypes was planted as a comparison. Number of pustules was recorded weekly, and resistant criteria was rated based on the International working group on soybean rust IWGSR method. Lesion color (LC), sporulation level (SL), number of uredia (NoU), frequency of pustule which had uredia, and yield were also recorded. Among 28 genotypes tested, only one was categorized as resistant and 2 genotypes were susceptible. Resistant genotypes had few pustules, lower AUDPC values, low disease severity, and Reddish Brown lesion type. Soybean rust affected yield components, i.e. number of intact pods and yield per plant. Yield loses due to rust in this study varied from 5-89%, and the average was 51%. The set of lines from Tanggamus pedigree showed more resistant to rust but less tolerant compared to Sinabung pedigree. How to Cite Inayati, A., & Yusnawan, E. (2016). Characteristics of superior soybean breeding lines tolerancet to rust (Phakopsora pachyrhizi Syd.). Biosaintifika: Journal of Biology & Biology Education, 8(1), 47-55.

Kedelai merupakan komoditas aneka kacang nomor satu di Indonesia. Kedelai digunakan sebagai bahan baku pembuatan tempe dan susu kedelai. Kandungan protein yang tinggi dan cita rasa yang enak pada olahan tempe menyebabkan komoditas ini, masih menjadi bahan baku utama. Produktifitas kedelai dapat terhambat oleh pengaruh faktor biotik, seperti serangan jamur patogen. Phakopsora pachyrhizi merupakan patogen penting pada tanaman kedelai dan menyebabkan penyakit karat. Infeksi patogen ini menyebabkan tanaman menguning dan menua dini, sehingga berpengaruh terhadap pembentukan polong dan biji. Penelitian ini menggunakan lima puluh varietas kedelai untuk melihat respon ketahanan varietas terhadap infeksi patogen. Infeksi dilakukan secara alami di lahan endemik penyakit karat pada awal musim kemarau. Pengamatan terdiri dari gejala, skroring serangan dan penentuan kriteria ketahanan menggunakan metode IWGSR. Hasil penelitian menunjukkan bahwa terdapat dua puluh tujuh varietas yang memiliki tipe ketahanan rentan, dua varietas menunjukkan respon agak rentan, sembilan varietas menunjukkan respon agak tahan, dan dua belas varietas menunjukkan respon tahan. Varietas yang menunjukkan respon tahan adalah varietas kawi, mutiara 3, wilis, gepak kuning, dena 2, menyapa, detam 2, merbabu, argopuro, slamet dan pangorango. Informasi ini dapat menjadi salah satu pertimbangan dalam pemilihan tetua untuk perakitan varietas kedelai yang tahan penyakit karat daun.

Background: Mung bean is susceptible to Rhizoctonia solani infection. Applications of beneficial microorganisms such as Trichoderma are promising for controlling pathogens and promoting plant growth. Methods: This study investigated growth performance and metabolic changes in mung bean seedlings during interaction with R. solani and Trichoderma virens using Gas Chromatography-Mass Spectrometry (GC-MS). Result: Mung bean infected by R. solani caused root rot and wilting. T. virens treatment reduced the disease severity in infected seedlings and promoted mung bean growth. Seventy-eight metabolites were identified in root extracts and dominated by sugars and fatty acids. The sugars, fatty acids and organic acids were significant metabolite groups that changed in response to pathogen infection and/or T. virens treatment. Five metabolic pathways particularly pyruvate metabolism, glyoxylate and dicarboxylate metabolism, sulfur metabolism, citrate cycle (TCA cycle) and phenylalanine, tyrosine and tryptophan biosynthesis altered significantly based on a metabolic pathway analysis. Acetic acid and aconitine had important roles in mung bean response to R. solani infection and/or T. virens treatment.

Rhizoctonia solani is an important soil-borne pathogen that devastated mung bean plants in Indonesia. Until now, there are no varieties that are resistant to infection with this pathogen. Thirty mung bean genotypes from different countries were evaluated for R. solani resistance. The changes in the physiology and biochemistry of mung beans affected by R. solani infection were investigated. This study showed that thirty genotypes tested were clustered into three groups by Euclidean distance and ward’s method based on a number of damping-off incidents, mortality rate, and a number of pods. R. solani infection causes physiological damage such as necrosis of guard cells, tissue collapse, and plant death, particularly in the early stage of plant growth. Seed rot, cotyledon rot, and damping-off were the three most prevalent symptoms. The shoot and root fresh weight, shoot and root length, as well as the number of pods, were reduced due to R. solani infection. Total phenolic and flavonoid content increased in mung bean seedlings under stress conditions. However, antioxidant activity was lower compared to the control untreated plant. As a response to disease attacks, phenylalanine ammonia-lyase (PAL) and tyrosine ammonia lyase (TAL) accumulations in the tolerant variety were remarkably higher than those in a susceptible variety. A similar trend was also observed in peroxidase and polyphenol oxidase activity. The results obtained in this study indicate that the mung bean resistance mechanism against R. solani was related to the synthesis of phenolic metabolites.