The success of disease control is largely determined by the validity of information about the type of causal-pathogen. Fusarium oxysporum f. sp. cepae (FOC) was reported to attack shallots and cause leaf twisting disease in Indonesia. We have conducted researches to investigate the causal agent of Fusarium disease and carried out growth tests on nine genotypes of shallots to determine the disease severity and disease indexes, and the correlation between diseases several agronomic traits. Thirty-five strains of Fusarium spp were isolated from wilted shallots tree and bulbs. Based on morphological characterization and rapid test to the isolates, they were identified as F oxysporum, F verticillioides, F solani and F proliferatum. The shallot genotypes that showed a tolerant response to FOC isolates tested were only Sumenep variety. Mentes, Tajuk, Batu Ijo, and Bima Brebes varieties show susceptible response.

<p class="abstrakinggris"><span class="tlid-translation">Variation within bulb tunics has been used to determine the genetic diversity in <em>Allium</em> species, including shallots</span><span class="tlid-translation"><span>. </span></span>However, no such study has been reported for shallots of Indonesia. The study aimed to analyze the genetic diversity of the Indonesian shallots based on the bulb-tunic patterns. Thirty-five shallot genotypes from main production centers in Indonesia were used. The ultrasculptures of the bulb tunics were examined by light microscopy, including the inner surface and cell shape patterns of the bulb tunics. The phenotypic data, i.e. quantitative and qualitative traits were subjected to the descriptive statistics, principal component, correlation, regression, and clustering analyses. The results showed that the bulb-tunic cell patterns were varied, which shared almost identical with 13 <em>Allium</em> species. Total bulb weight per genotype showed the greatest variation (cv = 89.10%) and significant correlation with bulb weight per plant (r = 0.773). The principle component analyses showed the cumulative proportion of 78% of the total morphological variation in all shallot genotypes. Based on clustering analysis, the genetic variation of Indonesian shallots are grouped into twelve clusters with 50% genetic similarity. The study indicates that Indonesian shallots are genetically varied and could be useful for further utilization in their genetic improvement program.</p>

ABSTRACT

Abstract. Herlina L, Istiaji B. 2020. The use of effector gene based-markers to facilitate identification of Fusarium sp. infected shallot in Java, Indonesia. Biodiversitas 21: 4677-4685. One of the most important diseases and become challenge in breeding resistant variety of shallots in Indonesia is Fusarium disease, caused by Fusarium oxysporum f.sp. cepae (FOC). To discriminate the F. oxysporum into forma speciales is uneasy, often managed through laborious and time-intensive disease assays., therefore molecular approaches become the most relevant choice. FOCs from Indonesia were examined by molecular criteria based on putative and effector genes-based markers, i.e.: SIX-genes, C5-gene, and CRX1-2-genes. The alignment analysis discovered some regions which sequences highly contained conserved bases, while amplification result bands vary in size, between 400 - 500 bp. The combined of 7 SIX-genes primers and 3 effector primers (C5 and CRX1-2) used in the clustering analysis of 15 FOC isolates in this study showed that they succeeded in separating 15 FOC isolates into 4 groups through NTSys. Clustering analysis showed that those markers succeeded in grouping 15 FOC isolates into different clades (by coefficient of similarity: 0.69). Phylogenetic analysis based on CRX genes sequence as putative effector genes confirmed that  CRX1 and CRX2 genes were able to classify the FOC into their forma speciales. Those effectors genes are potential to serve as marker-templates to facilitate identification of FOC which infested shallots in Indonesia.

Abstract. Wiyono S, Istiaji B, Triwidodo H, Suryaningsih AS. 2020. Abundance of soil microbes, endophytic fungi and blast disease of paddy rice with three pest management practices. Biodiversitas 21: 4234-4239. Rice production in Indonesia faces a potential threat of pests and diseases. Biointensive Integrated Pest Management (Bio IPM) is a new approach based on natural and biological control, which effectively controls pests and diseases. However, the impact of this technology on soil microbes and endophytic fungi is almost unknown. The objective of the study was to investigate the effect of Bio IPM on abundance of soil microbes, endophytic fungi, and blast disease under field conditions. Three pest management types were tested i.e. conventional, reduced pesticides, and Bio IPM. Field experiment was set in four replications in randomized complete block design. Experiments were carried out in two seasons i.e. dry and wet season. Variables assessed during experiment were amount of soil bacteria, soil fungi, phosphate solubilizing bacteria, colonization of total leaf endophytes, colonization of Nigrospora sp., and blast disease severity. The results showed that the abundance of soil bacteria and phosphate solubilizing bacteria were significantly increased with Bio IPM whereas it was not found to be significant in soil fungi. Total endophytic fungi and Nigrospora sp. were found higher in Bio IPM especially in early growth stages. Bio IPM controlled neck blast more effectively than conventional and reduced pesticides, but it did not show any significant effect on leaf blast disease.