This study examined the impact of two bacterial strains, H05E-12 and H05R- 04, on alleviating non-irrigation-induced stress and its subsequent effects on the fruit productivity of sweet pumpkin plants. When subjected to non-irrigation-induced stress, the lipid peroxidation, proline, total phenol, and total soluble sugar content significantly decreased in plants treated with either H05E-12 or H05R-04 compared to the control. In a greenhouse experiment under non-irrigated conditions, H05E-12-treated plants exhibited higher stomatal conductance than the control, although there was no significant change in the soil plant analysis development (SPAD) value due to treatment. Upon re-watering, an increase in fruit diameter was observed in H05E-12-treated plants, and the L-ascorbic acid content in the fruit also showed a significant increase compared to the control. The H05E-12 strain was identified as Kushneria konosiri. To the best of our knowledge, this is the first report detailing the beneficial effects of K. konosiri on the alleviation of non-irrigation-induced stress and the promotion of plant growth in sweet pumpkin plants.

Endophytes are microorganisms that live in the internal tissues of plants without harming the host plants. In this symbiotic relationship, the host plants provide nutrients and shelter to the endophytes, in turn, endophytes can promote the growth of host plants and act as a biological control agents against plant pathogens. Plant-microbe interactions like this are noted for natural methods for sustainable agriculture and environmental conservation. However, in spite of the infinite potential, there are only a few reports on the endophytes present in ginseng. In this study, we isolated and identified the endophytes from Panax ginseng seeds and evaluated the biological activities (IAA production ability, nitrogen fixation ability, phosphate solubilization capacity, siderophore production ability, and antifungal activities) of the endophyte isolates. Eight different endophytes were identified by 16S rRNA sequencing. Most of the endophytes have antibiotic and plant growth promoting (PGP) activities. Particularly, PgSEB5-37E have the highest antibiotic activity, both PgSEB5-37B and PgSEB5-37H have high PGP traits such as an abilities to produce IAA, solubilize phosphate and fix nitrogen. These results indicated that the endophytes from P. ginseng seeds may have applicable value to many industries. In order to use the isolated endophytes, quantitative analysis and field tests are needed to be performed.

The endophytic bacteria were isolated from the rusty-root ginseng. This isolated bacteria were occurred the rusty-root ginseng with artificial inoculation. For the suppressing of rusty-ginseng, disinfectants, antibiotics, kitosan, micro-organisms and metabolites were tested to isolated endophytic bacterium. All of the isolated bacteria strains were sensitive sodium hypochlorite, however, some of isolated bacteria lines were sensitive to other tested materials. For example, D (didecyl dimethyl ammonium bromide), CIO2, ODDA (octyldecyl dimethyl ammonium chloride + diocyul dimethyl ammonium chloride + alkyl diethyl benzyl ammonium chloride), GD (glutaraldehyde + dimethy cocobenzyl ammonium chloride) suppressed some of bacteria strains. Otherwise, some of antibiotics (e.g. ampicillin, chloramphenicol, erythromycin, kanamycin, neomycin, rifampin, streptomycin, tetracycline) were sensitive to the isolated bacteria strains. All of isolated bacteria strainswere inhibitive to the mixed formation with neomycin and streptomycin, and neomycin and tetracycline. Both sodium hypochlorite and antibiotic mixing of neomycin and tetracycline were effective to prevention of rusty-root ginseng of sub-merging ginseng in the ginseng field.

적변삼은 인삼에서 흔히 볼 수 있으며, 농가에 커다란 경제적 손실을 주지만, 아직까지 주원인에 대해서는 밝혀지지 않았다. 본 연구는 적변삼의 발생원인을 밝히기 위하여 적변삼과 내생 세균과의 연관성을 검토하였다. 인삼의 내생 세균 밀도는 정상 인삼의 경우 0.96~1.5×102cfu/g fw에 불과하였으나 적변이 심한 경우는 0.37~5.1×107 cfu/g fw로 정상 인삼에 비하여 밀도가 매우 높았다. 적변삼에서 분리한 31개 균주는 적변정도의 차이는 있지만 적변을 유발하였다. 적변과 관련이 있는 세균은 대부분이 그람 음성균이었다. 적변을 유발하는 세균을 세균학적 특성과 16S rDNA의 염기서열 분석에 의해 동정한 결과 Agrobacterium tumefaciens, A. rhizogenes, Burkholderia phenazinium, Ensifer adharens, Lysobacter gummosus, Microbacterium Iuteolum, M. oxydans, Pseudomonas marginalis, P. veronii, Pseudomonas sp., Rhizobium leguminosarum, R. tropica, Rhodococcus erythropolis, Rh. globerulus, Variovorax paradoxus의 세균으로 동정되었다. 따라서 인삼적변의 발생은 내생세균의 침입 및 증식에 기인한 것으로 추정된다.