Advances in and prospects for Actinidia viruses

Kiwifruit (Actinidia spp.) is an economically important fruit crop worldwide. Before 2010, kiwifruit viruses had not received much attention; since then, more than 20 viruses infecting kiwifruit have been discovered. Some of these viruses cause severe yellowing, mosaic, necrosis, ringspots and other symptoms on leaves, seriously impacting yield and quality. Many of these viruses are widely distributed. This review summarizes recent research advances in the identification, genomic variation, distribution, transmission, detection, incidence, prevention and control of kiwifruit viruses and proposes directions for future research. Using virus-tested propagation material is the most economical and effective method for controlling kiwifruit viruses.

Molecular Variability and Host Distribution of ‘Candidatus Phytoplasma solani’ Strains from Different Geographic Origins

The knowledge of phytoplasma genetic variability is a tool to study their epidemiology and to implement an effective monitoring and management of their associated diseases. ‘Candidatus Phytoplasma solani’ is associated with “bois noir” disease in grapevines, and yellowing and decline symptoms in many plant species, causing serious damages during the epidemic outbreaks. The epidemiology of the diseases associated with this phytoplasma is complex and related to numerous factors, such as interactions of the host plant and insect vectors and spreading through infected plant propagation material. The genetic variability of ‘Ca. P. solani’ strains in different host species and in different geographic areas during the last two decades was studied by RFLP analyses coupled with sequencing on vmp1, stamp, and tuf genes. A total of 119 strains were examined, 25 molecular variants were identified, and the variability of the studied genes was linked to both geographic distribution and year of infection. The crucial question in ‘Ca. P. solani’ epidemiology is to trace back the epidemic cycle of the infections. This study presents some relevant features about differential strain distribution useful for disease monitoring and forecasting, illustrating and comparing the phytoplasma molecular variants identified in various regions, host species, and time periods.

Dothistroma septosporum Not Detected in Pinus sylvestris Seed Trees from Investigated Stands in Southern Poland

In recent years, the decline of pine stands in Europe, including Poland, has been caused by the emerging needle pathogen Dothistroma septosporum. Although this fungus appears to preferentially infect Pinus pini, P. pinaster or P. radiata in Southern Europe, it has been reported in stands of P. nigra, P. mugo and P. sylvestris from Southern Poland. Our preliminary tests of symptomatic needles of diseased pines, including black pine (P. nigra), showed the presence of both D. septosporum and D. pini—the latter as the first report in Poland. No other endophytic pathogen, i.e., Lecanosticta acicola or Cenangium ferruginosum, were found. More extensive molecular surveying based on β-tub2 amplification of DNA in needle samples from 72 seed trees of P. sylvestris in nine different Forest Districts of Southern Poland did not find the presence of D. septosporum. Our study revealed that the seed trees from which we collected propagation material were free from the pathogen, and its endophytic behavior was not confirmed in our testing. Consequently, these investigated trees of P. sylvestris should be suitable for seed collection and propagation, following the requirements of “good” phytosanitary quality as “pathogen-free” pine seeds used for reforestation.

PENGARUH PEMBERIAN PUPUK KOTORAN KAMBING DAN ATONIK TERHADAP PERTUMBUHAN SETEK DAUN MAHKOTA NENAS (Ananas comusus L. Merr) KUALU PADA MEDIA GAMBUT

The Kualu pineapple propagation technique uses crown bud cuttings which is made as a pineapple plant propagation material for peat media that is added with goat manure and several concentrations of Atonic. The aim is to obtain an effective source of cutting material for the procurement of Kualu pineapple seedlings cultivated on peat soil. This research used a Completely Randomized Design (CRD) factorial with two factors. First factor was the dose of goat manure at levels 0, 10, 20, and 30 g/polybag dan second factor was various atonic concentrations at levels 0, 2, 4, and 6 ml/L. The data were statistically analyzed and further tested for honest real difference (BNJ) at the 5% level. The results obtained from the interaction of the two treatment factors were significantly different to the time of shoot emergence and the percentage of shoot life. There was no significant difference in seedling height and number of leaves, as well as the main effect of each treatment. Crown shoot cuttings planted on peat media added 20 g/polybag of goat manure and 4ml/l Atonic obtained a better source of cutting material to be used as a source of seeds than others. The success of obtaining seeds from crown leaf cuttings sources through this research has answered that crown leaf cuttings have potential and great opportunity to be developed.

Ceratocystis ficicola causing a serious disease of Ficus carica in Greece

Ceratocystis ficicola causes vascular wilt of fig trees in Japan, invading root systems and the main stems eventually leading to tree death. In surveys from 2018 to 2020 in fig orchards in Greece, this fungus was detected in two separated regions. The fungus was consistently isolated from infected wood and from rhizosphere soil. The isolates were identified based on multi-locus phylogenetic analyses of rpb2, bt1 and tef1 gene regions and detailed morphological characteristics, including comparisons with an ex-type isolate of C. ficicola from Japan. The pathogenicity of Greek isolates was proven on Ficus carica and F. benjamina plants. Ceratocystis ficicola is a soil-borne pathogen, and the occurrence of vascular wilt outbreaks suggest that the pathogen spreads within and between orchards with infested soil and wood debris during ploughing. The pathogen is also spreading in Greece with infected propagation material. This is the first detailed report of C. ficicola outside Japan, and there is concern over potential spread of the pathogen to other Mediterranean countries, where approx. 70% of the world fig production occurs.

Salix alba Clone Wilting Response to Heat Stress

The selection of most suitable propagation material, as well as the adjustment of existing seedling management practices, are gaining increasing importance to ensure the best outcomes under the long-term setting of climate change. One of the factors to consider is a predicted increase in the frequency and duration of high-temperature periods. Since heat often coincides with drought, these factors are typically assessed together, yet heat stress on its own has received less attention. In this study, we examined the effect of supra-optimal ambient temperature on nine Salix alba clone cuttings wilting under greenhouse conditions and sufficient moisture levels. Most plants are especially vulnerable to extreme conditions in early stages of development. Response to heat varied between clones but, overall, shoots that were taller than 350 mm were more sensitive to heat stress. The pruning of excess lateral shoots did not show significant improvement in heat tolerance. In total, 96% of the wilted cuttings proceeded to produce lateral shoots after the cessation of heat stress. It should be studied further if similar patterns are evident in field conditions and if earlier outplanting has a positive effect on cutting vitality.

Efektivitas Dakwah Hadis dalam Media Sosial: Analisis atas Teori Framing Robert N. Entman

Hadis preaching is now meeting new challenges in its succession of implementation, one of which is its touch with courage-based social media. Apart from optimizing the propagation material that is disseminated, it has also become an interesting topic in discussions of the development of modern dakwah. In this case, content framing (framing) is deemed appropriate to package the dakwah content offered to the people in order to have authority on social media. However, the question that can be offered is how can the theoretical application of the framing concept work on da'wah content on social media? Departing from this formula, the author will elaborate the dakwah paradigm through content from several accounts on Instagram, based on the hadith as the preaching material. The author provides segmentation of the @hadispedia and @pusatkajianhadis accounts as research objects using the theoretical synergy of Robert N. Entman's framing. This research is built on qualitative methods that are oriented towards the context of reality and data analysis of digital literature. The author will examine the focus of the problem with a descriptive-explorative orientation in order to obtain an optimal and comprehensive understanding. The argument from this research is that the concept of framing actualized on the preaching of hadith content, especially on @hadispedia and @pusatkajianhadis accounts, can increase the effectiveness of the implementation of da'wah on social media.

Cadophora sabaouae sp. nov. and Phaeoacremonium species associated with Petri disease on grapevine propagation material and young grapevines in Algeria

A field survey conducted on asymptomatic grapevine propagation material from nurseries and symptomatic young grapevines throughout different regions of Algeria yielded a collection of 70 Phaeoacremonium-like isolates and three Cadophora-like isolates. Based on morphology and DNA sequence data of β-tubulin (tub2) and actin (act), five Phaeoacremonium species were identified including Phaeoacremonium minimum (22 isolates), P. venezuelense (19 isolates), P. parasiticum (17 isolates), P. australiense (8 isolates) and P. iranianum (4 isolates). The latter two species (P. australiense and P. iranianum) were reported for the first time in Algeria. Multi-locus phylogenetic analyses (ITS, tub2, tef1) and morphological features, allowed the description of the three isolates belonging to the genus Cadophora (WAMC34, WAMC117 and WAMC118) as a novel species, named Cadophora sabaouae sp. nov. Pathogenicity tests were conducted on grapevine cuttings cv. Cardinal. All the identified species were pathogenic on grapevine cuttings.

Agronomic Performance of Temporary Immersion Bioreactor – Derived Potato Microtubers in a Peruvian Low Input Cropping Agriculture System

Potato cultivation is limited by a lack of access to quality propagation material. The application of micropropagation techniques combined with the diagnosis and sanitation of the main pathogens of the crop, has contributed to increased production efficiencies. In this regard, the use of temporary immersion bioreactors (TIBs) has improved the quality of microtubers micropropagated along with savings in costs of production. With the final goal of applying these technologies for commercial production, the current study investigated the agronomic performance of Peruvian Canchan potato microtubers derived from TIBs (basic agamic seed 1 and 2) under low-input agro-technology in the coastal zone of Peru. The results indicated that following 75 d of growth, plants derived from microtubers produced in TIBs displayed slower vegetative growth than those from conventional tubers. However, at harvest, these differences were no longer apparent. Although plants raised from conventional tubers produced the highest fresh mass of tubers, significantly more propagules were produced by plants regenerated from basic agamic seed 1 and 2 derived from micropropagation in liquid media. These results demonstrate that much more planting material (seed tubers) can be obtained from microtubers in the field (basic agamic seed 1) than from the conventional commercial seed tubers.