Konfirmasi Mikroba Endofit Penyebab Kontaminasi pada Kultur Jaringan Kangkung (Ipomoea aquatica Forssk.) Tanaman kangkung secara alami bersimbiosis dengan mikroba endofit, yang berpotensi menjadi kontaminan pada kultur jaringan kangkung karena berada di dalam jaringan dan sulit dijangkau saat proses sterilisasi eksplan. Tujuan penelitian ini adalah mengonfirmasi mikroba endofit penyebab kontaminasi pada kultur jaringan kangkung ‘Tetraploid’ sehingga dapat menjadi informasi awal untuk metode sterilisasi yang efektif. Sebanyak 14 sampel kontaminan pada media tanam kultur jaringan kangkung diisolasi dan diidentifikasi secara molekuler berdasarkan gen 16S rDNA untuk bakteri, daerah D1/D2 dari gen LSU rRNA untuk khamir, dan daerah ITS dari gen rDNA untuk jamur. Keragaman jenis mikroba yang teridentifikasi dibandingkan dengan keragaman jenis mikroba endofit dari jaringan tanaman kangkung yang ditanam pada media kultur jaringan tidak terkontaminasi mikroba, media kultur jaringan terkontaminasi mikroba, media tanam campuran tanah steril dan tidak steril, serta kangkung yang didapatkan dari pasar. Hasil penelitian ini mengonfirmasi bahwa khamir endofit dari kelompok Ustilaginaceae (basidiomycetous yeast) yang berasal dari jaringan tanaman kangkung sama dengan jenis kontaminan yang mengontaminasi media kultur jaringan kangkung ‘Tetraploid’. Khamir dari kelompok Ustilaginaceae (basidiomycetous yeast) tersebut juga merupakan mikroba paling dominan yang mengontaminasi media tanam kultur jaringan kangkung ‘Tetraploid’. Keywords: Ipomoea aquatica, kultur jaringan, mikroba endofit, morfologi, pohon filogeni Water spinach in nature lives in symbiosis with endophytic microbes, which have the potential to become contaminants in water spinach tissue culture because they are difficult to eliminate during the explant sterilization process. This study aimed to confirm endophytic microbes that cause contamination in the tissue culture of 'Tetraploid' water spinach so that it can provide initial information for an effective sterilization method. Fourteen contaminant samples in water spinach tissue culture media were isolated and identified molecularly based on the 16S rDNA gene for bacteria, the D1/D2 region of the LSU rRNA gene sequences for yeast, and ITS region of the rDNA gene for mold. The diversity of microbial species identified was compared with the diversity of endophytic microbial types from water spinach plant tissue grown on sterile tissue culture media, microbially contaminated tissue culture media, sterile and non-sterile soil mixed planting media, and water spinach obtained from the market. The results confirmed that endophytic yeast from Ustilaginaceae group (basidiomycetous yeast) derived from water spinach plant tissue was the same type of microbe that contaminated the 'Tetraploid' water spinach tissue culture media. The results gave new information that yeast from the Ustilaginaceae (basidiomycetous yeast) group was the most dominant microbe contaminating water spinach ‘Tetraploid’ tissue culture media. This group is endophytic yeast that lives within Ipomoea aquatica tissues.

Wild bananas are believed to have genes for resistance to biotic and abiotic stress in nature, making them potential genetic resources for creating superior varieties. Wild banana seeds, such as Musa acuminata var. tomentosa are generally difficult to germinate in vivo, so that in vitro embryo culture technique is needed. This study aimed to increase embryo germination and regeneration of wild banana M. acuminata var. tomentosa by soaking the seeds as hydropriming. The treatment comprised of soaking the seeds in sterile distilled water for four periods of time: 0 (control), 1, 4, and 7 days. A total of 45 embryos for each treatment were planted on petri dishes containing MS + 0.5 mg/L BA + 1 mg/L biotin + 1 mg/L proline. The results showed that hydropriming increased the rate of embryo germination and regeneration. Seeds soaked for 1, 4, and 7 days successfully resulted in embryo germination percentages of 87%, 62%, and 62%, respectively, while the control unsoaked seeds germinated with a lower percentage of 42%. One-day soaking treatment was the most optimal treatment to increase the rate of germination and regeneration as well as obtained the best vigor as demonstrated by the highest average height of plantlets, number of leaves, and roots than other treatments. Thus, 1-day seed hydropriming is the best treatment for embryo rescue and regeneration of wild banana M. acuminata var. tomentosa

The purpose of this study is to determine the effect of internal factor with the earning management as a proxy, and eksternal factor with allowance for impairment of receivables as a proxy to the earning management. This study was a qualitative research with agricultural sector company as objects along 2012 to 2015. By using purposive sampling techiques intended that the data obtained more varied because it comes from varied sources. According to the results, it can be concluded that the internal factors of earning management with the other comprehensive income as a proxy had a positive influence on the prediction of bakruptcies in the agricultural sector and the external factors with external risk that described by premises allowance for impairment of receivables does not have an influence on the prediction of banrkruptcies in the agricultural sector in BEI.

The purpose of this study is to determine the effect of internal factor with the earning management as a proxy, and eksternal factor with allowance for impairment of receivables as a proxy to the earning management. This study was a qualitative research with agricultural sector company as objects along 2012 to 2015. By using purposive sampling techiques intended that the data obtained more varied because it comes from varied sources. According to the results, it can be concluded that the internal factors of earning management with the other comprehensive income as a proxy had a positive influence on the prediction of bakruptcies in the agricultural sector and the external factors with external risk that described by premises allowance for impairment of receivables does not have an influence on the prediction of banrkruptcies in the agricultural sector in BEI.