Influence of Integrated Approach of Azotobacter and Nitrogen Fertilizer on Various Morpho-Physiological and Biochemical Parameters of Brassica Oleracea L. var. capitata

This study was formulated to evaluate the impact of bacterization with Azotobacter of two cabbage genotypes (Pusa Early golden acre and Pusa drum head) under field conditions. The study was performed in herbal garden of Jamia Hamdard, New Delhi. The plants were treated with graded treatments (60,120,180 kg N ha-1) of N alone and in combination with seedling inoculation withAzotobacter. The plants were sampled and tested for various morpho-physiological and biochemical parameters. Chlorophyll content, NR activity, protein content, sugar content and phenol content was found to be significantly higher in plants treated with N in combination in Azotobacter. Thus, the use of Azotobacteras a supplement or biofertilizer in integrated nutrient management systems was highly recommended to minimize the application rates of synthetic fertilizers and attain the goal of sustainable agriculture.

Induction of Defense Responses in Pinus sylvestris Seedlings by Methyl Jasmonate and Response to Heterobasidion annosum and Lophodermium seditiosum Inoculation

The induction of defense responses in Pinus sylvestris L. seedlings by methyl jasmonate (MeJA) was investigated in three experiments. Two different MeJA application methods were tested, and induction of defense responses was assayed by seedling inoculation with Heterobasidion annosum (Fr.) Bref. and Lophodermium seditiosum Minter, Staley and Millar. In the first experiment, five-year-old P. sylvestris ramets of one clone were directly treated with MeJA, followed by inoculation with H. annosum. In the second experiment, open-pollinated Scots pine seedlings were treated with MeJA by direct spraying and vaporization, and inoculation with H. annosum was done using a slightly modified protocol. In the third experiment, open-pollinated Scots pine seedlings were treated with MeJA by vaporization and inoculated with L. seditiosum. Direct application of MeJA induced seedling mortality, and in some cases, decreased resistance to inoculation with H. annosum. Application of MeJA by vaporization was less stressful for seedlings, and resulted in increased resistance to both H. annosum and L. seditiosum. In addition, an unforeseen Neodiprion sertifer (Geoffroy) and Hylobius abietis L. infestation provided anecdotal evidence of the efficacy of MeJA in inducing resistance to insect pests as well. Further studies are required on the induction of resistance to additional diseases and pests. Induced resistance could be used as a possible protective mechanism for Scots pine seedlings prior to planting during reforestation of stands to increase vitality and survival.

Migration and Multiplication of Pathogenic Bursaphelenchus xylophilus Isolates of Diverse Geographic Origins

Unfavorable pine wilt disease expansion predictions require a rapid advance in genetic breeding against the causative agent of this disease, Bursaphelenchus xylophilus. The main strategy for breeding more resistant trees to B. xylophilus, is the use of highly virulent isolates in inoculation experiments. Different inoculation assays were conducted on Botrytis cinerea cultures, in addition to P. pinaster and P. radiata branch sections and seedlings. Seven virulent isolates of different geographic origin (The Japanese nematode isolates S10 and Ka4, the Portuguese Pt72CH and Pt72T, the Spanish SpSA1 and SpPO1, and the American USA745.) were used in the experiments. The main aim of this work is to investigate differences among the seven isolates. The experiments determined that the studied isolates are significantly different. On fungal culture, the isolate from the USA showed the highest multiplication rate. Both seedling inoculation and branch sections experiments pointed to the Portuguese isolate Pt52T and the Spanish SpPo1 as the most virulent to P. pinaster. Conversely, higher numbers of the Pt72CH isolate passed through P. pinaster branch sections. The most virulent isolate for P. radiata was the Japanese S10, though it only showed significant differences in mortality when compared to the Spanish SpSA1. These results suggest that B. xylophilus have differential host specificities. The supplementary material depicts the methodology used in the inoculation assays, as well as shows figures of the most relevant results.

DNA Marker-Based High-Throughput Identification of Downy Mildew Infected and Non-Infected Sunflower Plants

Developing hybrids, resistant to causal pathogen of Downy mildew (Plasmopara halstedii (Farl.) Berl. & de Toni), is one of the critical tasks in sunflower breeding. Molecular markers have advanced breeding practice in the past decades, however there are still unmet needs for reliable high-throughput (HT) selection of the pathogen resistant starting material and differentiation of the plants infected by different pathogens. In this study, we tested the known DNA marker (308 bp fragment from ribosomal DNA of P. halstedii) for detection of pathogen in different tissues of sunflower plant and at different stages of plant development. Specified DNA marker was re-validated in the total DNA, isolated from sporangium as well as from seedlings of infected pathogen resistant/susceptible inbred lines of Ukrainian breeding and 60 F2 crosses. An independent set of field grown plants with unknown resistance to P. halstedii, having symptoms of the bacterial/fungal/viral pathology were used for HT screening and genotypes, infected with downy mildew, were successfully identified. Pathogen appeared to be concentrated in the vessels of sunflower leaves, in contrast to parenchymal tissue. Our study demonstrates an addition to whole seedling inoculation technique of P. halstedii detection, which allows HT identification of the pathogen infected and non-infected sunflower plants.

Screening Progenies of Mexican Race Avocado Genotypes for Resistance to Phytophthora cinnamomi Rands

Because of the low availability of avocado rootstocks with resistance to Phytophthora cinnamomi, it is necessary to search for genotypes that offer resistance and that could be used as commercial rootstocks. The objective of this study was to select progeny from the genotypes of Mexican race avocado plants that are resistant to P. cinnamomi. Seedlings from 12 avocado genotypes were placed in containers inoculated with a mycelial suspension of P. cinnamomi. Signs of disease in the upper part of the seedlings were registered every 3 days for 8 weeks using a visual scale of damage severity. The χ2 test (P < 0.009) showed significant differences among the genotypes evaluated, with ‘Todo el Año’ being the most resistant, as demonstrated by its rating of 70% asymptomatic seedlings, followed by ‘Plátano’ with 40%. The most susceptible genotypes were ‘María Elena’, ‘Silvestre’, and ‘Hass’, with 100% mortality. Seedling inoculation facilitated the detection of resistance to P. cinnamomi. ‘Todo el Año’ showed resistance toward P. cinnamomi. Therefore, individuals of its offspring could be recommended for use as rootstocks after confirming their resistance with a second evaluation, as well as performing tests in multiple localities to demonstrate their productive behavior after grafting.

Tanggap Pertumbuhan Aren (Arenga Pinnata (Wurmb) Merr.) Diinokulasi Dengan Fungi Mikoriza Arbuskula Terhadap Pengapuran Di Lahan Pasca Tambang Batubara

Sugar palm is one of local plants spesies that may potential for reclamation program because can be planted under the stands of forest crops. Forest crops can be shade seedlings sugar palm from direct sunlight because the growth of sugar palm is relatively slow. Sugar palm can be useful even without cutting down the trees. Previously, sugar palm had been planted at PT Berau Coal and had produced fruit. The research was conducted at coal post-mining land of PT Bukit Asam, Tanjung Enim, South Sumatera. The research using combination of AMF and liming treatment is as follows, ie MaK0 (control), Mak1 (seedling with AMF without inoculation; liming 30 g plant-1), MiK0 (AMF indigenous seedling inoculation; without liming), MiK2 (AMF indigenous seedling inoculation, liming 60 g plant-1), MmK0 (AMF mycofer seedling inoculation; without liming), and MmK3 (AMF mycofer seedling inoculation, liming 120 g plant-1). The results showed that sugar palm could be grown in the coal post-mining land. The combination of AMF and liming treatment did not significant effect on observed variables of plant height, rachis length, diameter, leaves number, number of spore and root cholonization. Sugar palm seedlings that have been infected with AMF could be grown and provide a good growth response even without liming.Keywords : Arbuscular Mycorrhizal Fungi (AMF), marginal land, sugar palm

Validation of Inoculation test and Screening for Resistance Sources of Mustard-Rapeseed Cultivars in Bangladesh Against Alternaria brassicicola

Alternaria leaf spot or black leaf spot caused by Alternaria brassicicola is the devastating diseases of mustard-rapeseed in Bangladesh, and can cause yield loss up to 60% every year. A total of 27 cultivars of Brassica spp. where Brassica rapa (13), B. juncea (5) and B. napus (9) were selected for resistance screening against A. brassicicola. Two inoculation methods viz. detached leaf and seedling inoculation were assessed for checking the validation of inoculation technique using cultivated mustard-rapeseed varieties in Bangladesh a method to measure resistance to A. brassicicola. A significant positive correlation between the results of two inoculation methods was found in this study. The detached leaf technique was more suitable due to development of clear symptoms on the leaves within 36 hrs, and suitable for screening large scale genotypes for resistance. The 3rd leaves of 30 day-old were more suitable for inoculation having severe symptoms than the 4th leaves. Among 27 Bangladeshi mustard-rapeseed cultivars all cultivars expressed susceptible reaction to A. brassicicola, except BINA Sharisha-8, as it had border line resistance.

Physiological and biochemical changes in Matricaria chamomilla induced by Pseudomonas fluorescens and water deficit stress

Environmental stresses and rhizosphere microorganisms affect growth parameters and accumulation of active ingredients especially in plants with medicinal properties. The present study examined the effects of chamomile (<em>Matricaria chamomilla </em>L.) seedling inoculation with <em>Pseudomonas fluorescens</em> PF-135 strain on its growth parameters, photosynthetic pigments, proline, malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) content, and essential oil concentration at both regular watering and water deficit experiments. Based on the obtained results, water deficit stress reduced root dry mass, and flower fresh and dry mass as well. However, amount of H₂O₂ and MDA in root and shoot tissues were considerably lower in inoculated plants compared to non-inoculated ones under both normal watering and water deficit regimes. It indicates that lipid peroxidation and production of reactive oxygen species has been diminished in inoculated plants. Also, essential oil content in inoculated plants significantly increased compared with that of non-inoculated ones under water deficit stress condition. It can be concluded that <em>P. fluorescens </em>PF-135 strain has an outstanding potential to alleviate adverse effects of water deficit on plant growth, and hence can be used as an excellent PGPR in order to boost chamomile productivity especially under water deficit stress condition.

Identification of Resistance to Fusarium oxysporum f. sp. niveum Race 2 in Citrullus lanatus var. citroides Plant Introductions

Fusarium wilt (FW) is a major disease of watermelon in North America and around the world. Control of this disease is difficult because the soilborne causal agent Fusarium oxysporum f. sp. niveum (Fon) produces chlamydospores that remain infectious in the soil for many years. Although various levels of resistance to Fon Races 0 and 1 exist in watermelon cultivars, no resistance to Race 2 or 3 has been reported. In this study, we used seed and seedling inoculation procedures to screen 110 U.S. PIs of wild watermelon (Citrullus lanatus var. citroides) for resistance to Race 2 FW. Of these 110 accessions, 15 showed significantly higher resistance to Fon Race 2 than that found in the watermelon cultivars Sugar Baby or Charleston Grey as well as in the C. lanatus var. citroides PI 296341 that was reported to contain resistance to FW. PI 271769, another C. lanatus var. citroides that was previously reported as containing resistance to FW, is among the 15 resistant accessions described here. These 15 accessions are potential sources for resistance to Race 2 FW in watermelon breeding.