Volume 25 (2017): Issue 2 (December 2017)

One purpose of assessing the soil alive and active community is the identification of beneficial bacteria to use them as biological fertilizers, replacing or supplementing synthetic fertilizers. Such biofertilizers are predicted for the sustainability of agricultural production, especially for low input systems such as saffron fields. The aim of this work was to isolate and identify saffron rhizobacteria and to evaluate their possible effects on saffron growth. During 2013/14, some bacteria were isolated from the rhizosphere of the saffron plantations of different age in Gol village, Birjand, Iran. In total, 12 bacteria species were identified based on phenotypic traits and 16S rDNA sequences analysis. The strains were identified as B. subtilis, B. anthracis, B. cereus, B. megaterium, Bacillus sp., Paenibacillus, Pseudomonas fluorescens, P. putida, Escherichia coli, Pectobacterium sp. and Pantoea sp., with the dominant population belonging to the genus Bacillus. In the field study, inoculation of soil with these strains did not affect the leaf dry weight of the cultivated saffron, however, the strains of P. fluorescens increased the leaf area while P. fluorescens, Paenibacillus, Pectobacterium and B. megaterium increased the number of daughter corms and Azotobacter, B. cereus, B. subtilis and B. megaterium increased the corm weight. Our finding revealed that some bacteria present in the soil of perennial saffron plantations have a promising potential for developing as a plant growth promoting rhizobacteria.

Canker and needle blight of Araucaria heterophylla (Norfolk Island pine) trees were observed during the surveys conducted in Addis Ababa and Adama cities (Ethiopia) from November to December 2016. The main objective of this study was to investigate fungal pathogens that cause diseases on Araucaria heterophylla trees. Six localities with Araucaria heterophylla plantings were purposively surveyed for disease symptoms. Samples from symptomatic parts of trees were collected, surface sterilized, cultured on PDA and morphologically identified for genus and species. A total of 36 isolates of fungi were identified. Based on macro- and microscopic morphological features of the colonies, the fungal isolates were found to be the genus Diplodia and species Lasiodiplodia theobromae (Pat.) Griffon & Maubl (syn. Botryodiplodia theobromae), the anamorph of Botryosphaeria rhodina (Berk. & M.A. Curtis) Arx. The pathogenicity test showed that the isolates of Lasiodiplodia theobromae, caused stem canker and needle blight on Araucaria heterophylla. This finding is important in the study of management options for future prevention and control of diseases in the country.

The purpose of this study is to investigate the effect of antioxidants on the budding success of three walnut genotypes under greenhouse conditions. After stratification, seeds were planted in a greenhouse at the end of autumn. After about 20 months, the seedlings grew up to 80 cm. The budding was done using scions of Z30, Z60, and B21 genotypes. Scions were immersed in polyvinylpyrrolidone (PVP) or ascorbic acid in the concentrations 2, 3, and 4 g·dm⁻³ for 1 h before budding. Percentage of successful budding was determined after one month. The results showed that genotype significantly affected the percentage of budding success, but no interaction between genotype and treatments was found. The antioxidant solutions significantly affected all the parameters studied in this research. Ascorbic acid with 3 g·dm⁻³ resulted in the highest percentage of budding success (86.66%); no significant differences were observed with 4 g·dm⁻³ of ascorbic acid and 3 and 4 g·dm⁻³ of PVP. Furthermore, antioxidant solutions significantly affected the content of chlorophylls, and 3 g·dm⁻³ of ascorbic acid resulted in the highest content of chlorophylls in scion leaves.

Plums, sweet cherry, and sour cherry trees were spaced 4.5 m × 1.5 m to be trained to “Y” and “V”-trellising systems for mechanical harvesting, with a canopy contact harvester, attending to obtain fruits meeting the requirements of the fresh fruit market. The applied trellising systems were compared with the standard central leader system at the same spacing. The most of trellised trees grew less vigorously than the standard trees, and after 3 years of training, the trees were suitable for mechanical harvesting with the harvester designed at the Research Institute of Horticulture in Skierniewice. The trellised trees were able to set as many fruitlets as those grown in the form of central leader and gave a comparable yield, but differences between cultivars were significant. Light interception in the third year after planting was lower for trees of sour cherry and plum growing in the “Y”-20° and “V” in comparison to the trees with central leader. Illumination of trellised canopies at the level of 0.7 and 1.5 m was the most favorable in “V” system when compared to control and “Y” training systems. Cost of construction for the trellising systems of stone fruits calculated per 1 ha was two times higher when compared with the standard system.

Agriculture and modern biotechnology are increasingly becoming interdependent, and many new techniques have brought new opportunities for enhancing production and marketing. Germplasm storage is an alternative for the conservation of plant genetic diversity, contributing to the improvement and maintenance of propagation programs for species of interest. In this work, banana corms were collected as plant material from relatively young commercial plantations of three different cultivars: ‘Williams’, Valery (AAA genome; Cavendish subgroup), and ‘Barraganete’ (AAB genome; Plantain subgroup). Their shoot tips were introduced into in vitro conditions, and subcultured monthly to obtain the required number of shoots. The shoots were subsequently rooted and stimulated to invigoration in order to extract apical meristems (0.8–1.0 mm), which were prepared for cryopreservion in liquid nitrogen (−196 °C) following pre-conditioning in PVS2 vitrification solution. Thereafter, the explants were rapidly thawed and then recovered and regenerated using two different methods – by Panis (2009) and Korneva et al. (2009) – consisting of two different sets of recovery and subsequent regeneration media. Statistical analysis of the results showed that the banana cultivar ‘Williams’ demonstrated higher survival and regeneration rates after cry-opreservation using the Korneva method, whereas in cultivars ‘Valery’ and ‘Barraganete’, there were no significant differences between the tested methods. The ‘Barraganete’ cultivar had the lowest survival and regeneration rates, regardless of the applied method.

The cultivated pear is an economically important fruit tree species of genus Pyrus in which often gametophytic self-incompatibility occurs. Therefore, this species need to be pollinated by cross-compatible cultivars that bloom in the same time. Selection of appropriate pollinizers for pear cultivars is very important to produce commercial yield. ‘Sebri’, ‘ Shahmiveh’ and ‘Natanzi’ are the best commercial cultivars in Iran, but the lack of a suitable source of pollen can reduce productivity. In order to select the most suitable pollinizer for these pear cvs, an experiment was conducted in which they were considered as pollen recipients and ‘Coscia’, ‘Bartlett’ and ‘Sardroud’ along with ‘Sebri’, ‘Shahmiveh’ and ‘Natanzi’ were evaluated as pollen donors. This research was conducted as a factorial experiment in randomized complete block design for four years. Recipient and donor cultivars had almost overlapping flowering time. The flower buds on selected branches were emasculated at balloon stage and then were counted and isolated with cotton tissue bags. Pollen grains of these pollinizers were collected in the laboratory. Isolation bags were taken off from the branches and emasculated flowers were pollinated with pollen grains of listed pollinizers during receptibility of stigma. The number of pollinated flowers was counted, and branches were covered again with the bags. The results showed that for ‘Sebri’ the best pollinizer was ‘Coscia’ with 5.7% fruit set, for ‘Shahmiveh’ ‘Bartlett’ cv. with 5.8% of fruit set and for ‘Natanzi’, ‘Shahmiveh’ with 5.5% of fruit set.

The purpose of this study was to evaluate the effect of humic acid (HA) applied at 4.8, 9.6 and 14.4 kg·ha⁻¹ on the growth and productivity of two tomato hybrids Nema 1400 and Platinium 5043 under hot continental climate. HA was applied twice to soil: the first one – three weeks from transplanting and the second one, after one week from the first application, in both seasons. Application of HA during the summer season targeted a great results on tomato plant growth and productivity. HA at 14.4 kg·ha⁻¹ in-creased the vegetative growth of tomatoes (plant height and fresh weight) and flowering parameters (number of flower clusters and flowers per plant) as well as yield characters (fruit number per plant and fruit weight, which resulted in higher early and total yield) in both seasons. HA application had the least impact on fruit number per plant, and on vitamin C and total soluble solids (TSS) concentration as compared with control.

The current research based on greenhouse experiment evaluates the impact of the Lactobacillus strains (Lactobacillus plantarum, Lactobacillus paralimentaris, Lactobacillus fermentum, Lactobacillus pentosus, and Lactobacillus buchneri) previously isolated from maize silage on the Fusarium verticillioides-infected maize plants. The growth parameters as well as catalase, superoxide dismutase, ascorbate peroxidase, and peroxidase antioxidant enzymes activity were investigated in one-month old seedlings, after inoculations with Fusarium or co-inoculations with Fusarium and the Lactobacillus strains. Application of Lactobacillus strains in maize seedlings significantly enhanced the plant growth and biomass. The best effect was observed when the L. buchneri was applied. It was revealed that inoculation with Fusarium stimulated antioxidant enzyme activity and co-inoculation with Lactobacillus strains reduced the enzyme activity, compared to Fusarium treatment alone. This is the first report that revealed the bioprotective role of Lactobacillus strains against F. verticillioides.

Four leafy vegetable species, spinach (Spinacia oleracea), amaranthus (Amaranthus viridis), fenu-greek (Trigonella foenum-graecum) and bathua (Chenopodium album), were extracted with three different solvents (80% ethanol, 80% acetone and water) for maximum recovery of phenol and antioxidant compounds in the extract. The results of extraction were compared with extraction from moringa (Moringa oleifera) leaves that is known as a very rich source of antioxidants. The study showed that, it is very difficult to justify a single solvent for extraction of antioxidant compounds from different plants. Results from different solvents used for extracting the bioactive compounds mostly depend on the type of compound extracted (polar/medium polar/non-polar) present in leafy matrices. Here, 80% acetone extract showed highest total phenol content in moringa leaves but the overall antioxidant activity in the leaves of four vegetables was observed to be better after extraction with 80% ethanol. Nevertheless, in most assays, independent of solvent used for extraction, the moringa leaves were the richest source of polyphenols and antioxidants.

The developmental stages of Callosobruchus analis were observed under laboratory conditions at 28 ± 2 °C and 72 ± 5% relative humidity. The results showed that female C. analis began to lay eggs within 24 hours and have an oviposition period of 8.50 ± 0.70 days and an average of 13.00 ± 0.50 eggs were laid by individual C. analis throughout their lifetime. The mean developmental periods from egg to larva and larva to pupa were observed to be 8.50 ± 0.79 and 4.50 ± 0.70 days, respectively. The unmated bruchids were observed to have lived longer than the mated bruchids as the unmated bruchids lifespan was on average 10.50 ± 0.81 days, as opposed to 2.50 ± 0.75 days for mated females. Adult male C. analis have an average antenna length of 2.96 ± 0.08 mm which is slightly longer than 2.42 ± 0.12 mm on average for female bruchids. The three botanical oil extracts from Capsicum frutescens, Anacardium occidentale and Xylopia aethiopica used at 10.0% concentration were not effective, as none of them resulted in a mortality rate of 50% when recorded 3 days after treatment.

Pesticides are applied to protect crops from a variety of insect pests but their application cause toxicity to plants that results, among others, in reduction of protein as well as amino acid contents. The present study is aimed at observing the effect of seed pre-soaking with 24-epibrassinolide (EBL) on the protein and amino acid content in the leaves of Brassica juncea L. grown in soil that is amended with pesticide im-idacloprid (IMI). Soil amendment with IMI resulted in a decrease in the contents in leaves of total proteins and 21 amino acids studied. Seed soaking with 100 nM of EBL resulted in the recovery of total protein as well as amino acid contents in leaves, when compared with plants grown in only IMI amended soils.