Determination of Biocontrol Potential of Bacillus spp. and Stenotrophomonas sp. against Macrophomina phaseolina in Sunflower

Macrophomina phaseolina is a soil pathogen known as charcoal rot and can cause up to 90% yield loss in sunflower under suitable conditions. The serious damage caused by chemicals used in the control of soil-borne pathogens to the environment and health has become one of the most important concerns in agriculture. Therefore, in our study, it was aimed to determine the in vitro antagonistic effects of various bacterial species against M phaseolina. A total of 38 bacterial strains were isolated from soil samples in the rhizosphere of Malva sylvestris (hibiscus), Vicia sativa (vetch), Cicer arietinum (chickpea), Papaver rhoeas (weasel), Carlina marianum (thistle), Glebionis coronaria (crown daisy) and Vicia faba collected from Urla district of İzmir. All bacterial strains exhibited antibiosis effect under in vitro conditions, but it was determined that 5 bacterial isolates among them showed a high inhibition zone and showed an average inhibition potential ranging between 55% and 74%. The most effective bacteria identified at species and genus level by Maldi biotyping (MALDI-TOF MS) were identified as Bacillus amyloliquefaciens, Stenotrophomonas sp. and Bacillus cereus (3 isolates), and these species showed that they can be important biocontrol agents in biological control against M. phaseolina.

Genetic Resistance of Lactuca spp. against Fusarium oxysporum f. sp. lactucae Race 1

Fusarium wilt of lettuce is caused by the pathogen Fusarium oxysporum f. sp. lactucae (Fol) and is a growing threat to global lettuce production. Fol was first detected in Florida in 2017 and was subsequently confirmed as race 1. Management strategies for this long-persisting soil pathogen are limited, time-consuming and expensive, and they may lack efficacy. Identifying diverse sources of genetic resistance is imperative for breeding adapted cultivars with durable resistance. The objectives of this study were to identify sources of resistance against a race 1 isolate of Fol in Florida, delineate the relationship between foliar and taproot symptoms, and investigate the inheritance of resistance and partial resistance in two F2 populations. Thirteen experiments were conducted in greenhouse and field locations to characterize the diversity of genetic resistance in the genus Lactuca. Leaf cultivars Dark Lollo Rossa and Galactic; romaine breeding lines 43007, 60182, and C1145; and iceberg breeding line 47083 consistently exhibited low foliar and taproot disease symptoms. Resistance was not identified among the wildtype Lactuca or primitive plant introductions (PI) in this study based on taproot symptoms. An additional test was conducted to study the segregation pattern of Fol resistance between one resistant and one susceptible accession (R × S) and one partial resistant and one susceptible accession (PR × S). The F2 population from ‘60182 × PI 358001-1’ fit the expected segregation ratio for a single recessive locus model, whereas the ratio for ‘Dark Lollo Rossa × PI 358001-1’ did not fit either recessive or dominant single locus models. These sources of resistance are potential candidates for developing commercial cultivars with multiple resistance loci against Fol race 1, especially for the Florida lettuce production system.

Backcross Aiming at the Resistance of Passion Fruit to Soil Pathogen

Brazil is the world's largest producer of passion fruit, however, the crop suffers from serious phytosanitary problems, as well as those caused by soil fungi. Thus, the objective of the present work was to estimate the genetic parameters and to select genotypes resistant to Fusarium solani species complex—FSSC in a segregating population from the first generation of backcross among P. edulis and interspecific hybrids, aiming at advancing generation in the genetic improvement program of passion fruit. The Interspecific Hybrid was used (IH) UNEMAT 142 resistant to colon rot, for generation advancement and to cultivate BRS Sol do Cerrado (Passiflora edulis Sims). In order to evaluate the resistance of the 27 genotypes of the first generation of backcrosses, inoculation with the FSUNEMAT 40 (F. solani) inoculum was performed. To estimate the components of variances, the method of maximum restricted likelihood (REML) was used and to select the best genotypes by the non-addicted linear prediction (BLUP). The variables that showed the highest heritability values were the survival period and the area under the lesion length expansion curve. The three families of backcrosses presented genotypes resistant to the fungus F. solani, however, by the methodology of mixed models REML/BLUP, only the genotypes BC1-22/1, BC1-22/2, BC1-22/3, BC1-22/4, BC1-22/6, BC1-22/7, BC1-113/3, BC1-113/7 and BC1-113/8, were selected to advance the generation of the UNEMAT passion fruit breeding program, therefore, they presented among the ten placed, mainly for the variable survival period (SP).

Soil Disinfestation Efficacy against Soil Fungal Pathogens in Strawberry Crops in Spain: An Overview

(1) Background: Strawberry cultivation is highly dependent on soil disinfestation for proper development. Since the definitive methyl bromide phase-out, other chemicals have been used as alternatives. This research provides an overview on the efficacies of soil disinfestation methods on controlling soil fungal diseases of strawberry. (2) Methods: The efficacy of several soil disinfestation methods on soil fungal pathogens (SFP: Fusarium spp. and Macrophominaphaseolina) was analyzed in experimental field trials during eleven growing seasons. (3) Results: Average efficiencies in reducing soil pathogen inocula for soil disinfestation techniques are given. Soil disinfestations with chloropicrin, allyl isothiocyanate, dazomet, 1,3-dichloropropene:chloropicrin, methyl iodide:chloropicrin, and dimethyl disulfide reduced Fusarium spp. and M. phaseolina soil inocula by more than 90%. Combination of solarization with organic manures (biosolarization) reduced Fusarium spp. soil populations by 80% and M. phaseolina by 79%. Reductions in plant mortality and increases in fruit yields over the untreated controls did not differ between chemically fumigated and biosolarized plots. (4) Conclusions: Soil fungal pathogens are effectively controlled by chemical fumigation of soils in intensive strawberry crops in Spain. In the case of mixed infestations of SFP with nematodes, the most efficient treatment in suppressing soil-borne diseases was soil fumigation with 1,3-dichloropropene:chloropicrin, but other alternative chemicals, such as allyl isothiocyanate, dazomet, and dimethyl disulfide, provided high efficacies in reducing the SFP inocula. Soil biosolarization is proposed as an effective alternative to chemical soil fumigation for strawberry cultivation in Southern Spain when SFP inocula is not remarkably high.

Burkholderia pseudomallei sepsis with osteoarticular melioidosis of the hip in a patient with diabetes mellitus

Melioidosis is caused by the tropical soil pathogen Burkholderia pseudomallei. Infection, usually in the form of pneumonia, disproportionately affects people with a risk factor for immune dysregulation and mortality remains high even with treatment. Climate change and increasing rates of diabetes render the populations of endemic areas increasingly vulnerable to the disease, which is emerging as a serious global health threat. We present here a case of a 68-year-old man from northern Australia with sepsis and osteoarticular melioidosis of the hip, and explore the links between diabetes mellitus and melioidosis, particularly with respect to musculoskeletal infection.

EFEKTIVITAS TEKNIK KONSERVASI LAHAN DALAM MENEKAN EROSI DAN PENYAKIT LINCAT

<p>Penelitian dilaksanakan di Desa Glapansari, Kecamatan Parakan, Kabupaten Temanggung pada bulan Maret sampai Desember tahun 2001 untuk mcngcvaluasi pengaruh penerapan teknik konservasi lahan dalam pengendalian erosi dan penyakit lincat terhadap erosi, sifat fisik tanah, populasi patogen, kematian tanaman, serta hasil tembakau. Perlakuan yang diuji adalah teknik pengendalian erosi yang meliputi penanaman rumput Setaria pada bibir teras dan tanaman Elemingia congesta pada bidang tampingan, seta pembuatan rorak di dasar saluran teras dan pengolahan tanah minimum. Perlakuan tersebut dikombinasikan dengan teknologi pengendalian penyakit lincat, yaitu penanaman galur tembakau tahan (BC3-C51) dan pembcian/penyemprotan mikrobia antagonis Aspergillus fumigatus dan Bacillus cereus. Rancangan yang digunakan adalah rancangan acak kelompok dengan dua perlakuan (konservasi dan kontrol) dan enam ulangan. Setiap satuan percobaan tersusun atas petak berukuran 22 m x 4 m dan masing-masing dipasang satu unit bak penampung erosi. Hasil penelitian menunjukkan bahwa penerapan teknik konservasi dapat menekan besanya erosi dari 30.2 ton/ha menjadi 16.7 ton/ha atau turun 44.8 %. Kombinasi teknik pengendalian penyakit lincat dapat menekan perkembangan patogen lincat dan mengurangi kematian tanaman tembakau sebesar 53.6%. Hasil daun tembakau basah dan rajangan kering pada perlakuan konservasi masing-masing 41.7% dan 42.1% dibanding kontrol.</p><p>Kata kunci: Tembakau, Nicotiana tabacum, tembakau temanggung. konservasi tanah, erosi, patogen tanah</p><p> </p><p>ABSTRACT</p><p>Effectiveness of land conservation technique in reducing soil erosion and lincat plant diseases</p><p>Field trial was conducted in Glapansari Village, Parakan, Temang¬ gung District from March to December 2001 to evaluate the effect of land conservation by controlling soil erosion and plant disease on soil erosion, soil physical characteristics, soil pathogens population, dead tobacco plant, and tobacco yield. The treatments were soil conservation technique by planting of Setaria grass on Ihe terrace edge and planting Elemingia congesta on the riser, and digging of sediment trap on the base of terrace ditch. The treatments were planting tobacco line (BC3-C51) tolerant to lincat disease combined with the application of antagonistic microbes (Aspergillus fumigatus and Bacillus cereus). The research used complete randomized block design with two treatments and six replications. Each expeimental units composed of plot sized 22 m x 4 m and soil erosion collector. Results showed that the land conservation technique reduced soil erosion rom 30.2 to 16.7 tones/ha or 44.8%. This technique reduced soil pathogen population and dead tobacco plant 53.6%. The land conservation technique increased signiicantly tobacco fresh leaves yield 41.7% and dried sliced tobacco yield 42.1 % compared to that of control.</p><p>Key words: Tobacco, Nicotiana tabacum, temanggung tobacco, soil conservation, erosion, soil pathogen <br /><br /></p>

TEKNIK KONSERVASI UNTUK MENEKAN EROSI DAN PENYAKIT LINCAT PADA LAHAN TEMBAKAU TEMANGGUNG

ABSTRAK<br />Masalah utama pada budidaya tembakau temanggung adalah erosi yang<br />mencapai 42,75 ton/ha dan serangan penyakit lincat yang dapat mematikan<br />tanaman sampai 80%. Untuk menekan erosi dan penyakit lincat tersebut telah<br />dilakukan penelitian yang dilaksanakan pada tahun 2002 di Desa Glapansari,<br />Kecamatan Parakan, Kabupaten Temanggung. Tujuannya adalah untuk<br />mengetahui pengaruh penerapan teknik konservasi lahan yang dikombinasikan<br />dengan pengendalian penyakit lincat terhadap erosi, kadar unsur hara tanah<br />tererosi, sifat fisik tanah, populasi patogen, persentase kematian tanaman, serta<br />hasil tembakau. Perlakuan yang diuji adalah teknologi konservasi lahan yang<br />meliputi penanaman rumput setaria pada bibir saluran pemotong lahan selebar<br />4 m, dan tanaman flemingia pada bidang vertikal saluran pemotong setinggi 0,5<br />m, serta pembuatan rorak di dasar saluran pemotong lahan yang mempunyai<br />kemiringan 43%. Perlakuan tersebut dikombinasikan dengan teknologi<br />pengendalian penyakit “lincat”, yaitu penanaman galur tahan (BC3-C51),<br />pemberian mikrobia antagonis A. fumigatus, penyemprotan dan pemberian<br />pestisida kimiawi. Mikrobia antagonis dan pestisida kimia disemprotkan pada<br />lubang tanam sehari sebelum tembakau ditanam. Penanaman bibit rumput<br />setaria dan flemingia serta pembuatan rorak dilakukan pada tahun 2000, yaitu<br />dua bulan sebelum penanaman tembakau musim tanam tahun 2000. Rancangan<br />yang digunakan adalah rancangan acak kelompok yang diulang 6 kali. Di<br />setiap petak perlakuan yang berukuran 22 m x 4 m dipasang sebanyak dua unit<br />bak penampung erosi, yaitu 1 unit bak penampung erosi untuk perlakuan<br />kontrol dan 1 unit untuk perlakuan teknik konservasi yang diletakkan di tengah<br />petak bagian bawah. Hasil penelitian menunjukkan bahwa penerapan teknik<br />konservasi pada lahan tembakau temanggung dapat menekan besarnya erosi<br />dari 30,22 menjadi 16,67 ton/ha/thn atau sebesar 44,84%. Penyemprotan<br />mikrobia antagonis pada lahan dengan teknik konservasi dapat menekan<br />perkembangan populasi patogen lincat dan mengurangi persentase kematian<br />tanaman tembakau. Hasil tembakau yang ditanam pada lahan dengan teknik<br />konservasi dan aplikasi pengendalian penyakit “lincat” ternyata lebih tinggi<br />42% dibanding hasil tembakau yang ditanam pada lahan kontrol.<br />Kata kunci : Konservasi lahan, erosi, tembakau temanggung, penyakit lincat<br />ABSTRACT<br />Soil conservation technique to reduce erosion and soil<br />pathogens of temanggung tobacco land<br />Mostly area cropping of temanggung tobacco is located in hilly land, so<br />that erosion and accumulation of disease are the main problems. To minimize<br />erosion and disease attacks, research had been done in Glapansari Village,<br />Parakan District, Temanggung in 2002 at site with slope of 43%. The aim was<br />to know the effect of soil conservation which was combined with soil disease<br />control techniques on soil erosion, eroded soil element, soil physics, soil<br />pathogens population, percentage of dead tobacco plant, and tobacco yield.<br />The treatments are soil conservation technique, planting of setaria grass and<br />flemingia in ridge terrace and digging of ditch pitch on the base of ridge<br />terrace. All of the treatments was established in 2000. The soil conservation<br />treatments were combined with application of antagonistic microbes (A.<br />fumigatus) and cropping of resistant tobacco line (BC3-C51). Randomized<br />Block Design with 6 replicates was used in this research. In each treatment of<br />22 m x 4 m plots, two units soil erosion collector were set, one unit was for<br />control treatment (without soil conservation and soil disease control techniques<br />or local farmer technology treatment) and the other for soil conservation<br />techniques. Results showed that soil conservation technique reduced soil<br />erosion from 30.22 to 16.67 tones/ha/year or 44.84%. Tobacco land that was<br />treated with soil conservation and soil pathogen control techniques had less soil<br />pathogen population and death tobacco plant than tobacco land without<br />treatments (control). Tobacco yield planted in land with soil conservation was<br />higher 42% than that planted in control land.<br />Key words : Soil conservation, erosion, temanggung tobacco, soil pathogen