PENGARUH PAKAN ALAMI YANG BERBEDA TERHADAP PERTUMBUHAN DAN KELANGSUNGAN HIDUP BENIH IKAN MAS KOI (Cyprinus rubrofuscus)

Penelitian ini bertujuan untuk mengetahui pengaruh perlakuan pemberian pakan alami yang berbeda terhadap pertumbuhan dan kelangsungan hidup ikan mas koi (Cyprinus rubrofuscus) dan mengetahui jenis pakan alami yang terbaik untuk meningkatkan kelangsungan hidup ikan mas koi (Cyprinus rubrofuscus. Metode yang digunakan adalah metode eksperimen Rancangan Acak Lengkap (RAL) dengan 4 taraf perlakuan dan 3 ulangan. Perlakuan A Artemia sp, perlakuan B cacing sutra (Tubifex sp), perlakuan C maggot BSF (Hermatia illucens) dan perlakuan D Wolffia arrhiza. Berdasarkan hasil analisis variansi, pertumbuhan panjang mutlak dan berat mutlak berpengaruh nyata (significant*), sedangkan kelangsungan hidup berpengaruh sangat nyata (highly significant**). Dari hasil penelitian diperoleh data pemberian pakan untuk pertumbuhan berat mutlak, pertumbuhan panjang mutlak dan kelangsungan hidup yang terbaik pada perlakuan A (Artemia sp) yaitu panjang mutlak 1,3 cm, berat mutlak sebesar 0,4 gram dan kelangsungan hidup sebesar 90%. Suhu perairan rata-rata 25,0-28,5 oC dan pH rata-rata 6,5-8,0.

Brassinolide Enhances the Level of Brassinosteroids, Protein, Pigments, and Monosaccharides in Wolffia arrhiza Treated with Brassinazole

Brassinolide (BL) represents brassinosteroids (BRs)—a group of phytohormones that are essential for plant growth and development. Brassinazole (Brz) is as a synthetic inhibitor of BRs’ biosynthesis. In the present study, the responses of Wolffia arrhiza to the treatment with BL, Brz, and the combination of BL with Brz were analyzed. The analysis of BRs and Brz was performed using LC-MS/MS. The photosynthetic pigments (chlorophylls, carotenes, and xanthophylls) levels were determined using HPLC, but protein and monosaccharides level using spectrophotometric methods. The obtained results indicated that BL and Brz influence W. arrhiza cultures in a concentration-dependent manner. The most stimulatory effects on the growth, level of BRs (BL, 24-epibrassinolide, 28-homobrassinolide, 28-norbrassinolide, catasterone, castasterone, 24-epicastasterone, typhasterol, and 6-deoxytyphasterol), and the content of pigments, protein, and monosaccharides, were observed in plants treated with 0.1 µM BL. Whereas the application of 1 µM and 10 µM Brz caused a significant decrease in duckweed weight and level of targeted compounds. Application of BL caused the mitigation of the Brz inhibitory effect and enhanced the BR level in duckweed treated with Brz. The level of BRs was reported for the first time in duckweed treated with BL and/or Brz.

WOLFFIA ARRHIZA (L.) HORKEL EX WIMM. RECORDS IN THE NOVOSIBIRSK REGION (WEST SIBERIA) - THE FIRST IN ASIAN RUSSIA

In 2020 the first record of Wolffia arrhiza was registered in Novosibirsk Region (West Siberia) in the floodplain lake. Wolffia arrhiza formed vast stands with an area of hundreds square meters and with high productivity. Besides monodominant communities, it was met as a component of the cenoses of such hydrophytes as Stratiotes aloides , Hydrocharis morsus-ranae , as well as of the helophyte communities formed by Typha latifolia and Eleocharis mamillata . According to local residents, the large stands of Wolffia was observed for some years, thus, most likely, the population winters safely at the latitude of Novosibirsk. The most likely source of Wolffia arrhiza appearance in the lake was a deliberate introduction from the aquarium. Although the probability of this plant entering to the lake from the waste water of the city septic tank of the Novosibirsk sewage waters also exists.