Tri Handoyo

Water deficit is one of the most critical factors for determining the growth and yield of sugarcane. Understanding the physiological and molecular mechanisms of sugarcane responses is essential for developing resilient cultivars. In this study, three sugarcane cultivars, NX04 (sensitive), BL (moderate), and NXI-4T (tolerant), were grown in a greenhouse for 2 months and then subjected to drought stress for 8 days after planting. Morphological variation showed that the tolerant sugarcane cultivar exhibits a longer root system and delays leaf chlorosis and rolling. Malondialdehyde (MDA) content was increased in the sensitive and moderate cultivars, although it slightly increased in the tolerant cultivars at 8 days after drought stress. The increase was accompanied by increases in proline content and in gene expression of the catalase (Cat) and ascorbate peroxidase (Apx) across all cultivars, which protect cells from oxidative damage. Interestingly, the expression of the photosynthetic Pepc (phosphoenolpyruvate carboxylase) and Sps (sucrose-phosphate synthase) genes was significantly decreased, whereas SPS activity increased under drought stress. This implies that the SPS protein may be regulated through post-translational modification. The expression of transcription factors (TFs) of NAC, rather than DREB, was significantly upregulated in the tolerant cultivar under 8 days of drought stress, in line with the delay of chlorosis.

Selada merah merupakan sayuran berdaun merah, mengandung antosianin sebagai sumber antioksidan serta bermanfaat bagi kesehatan. Selada merah kaya antosianin menjadi sayur yang menyehatkan, dimana kandungannya dapat ditingkatkan melalui cekaman abiotik, sehingga akumulasi antosianin pada daun lebih tinggi. Penelitian ini memodifikasi kualitas cahaya dengan memberikan warna cahaya lampu LED (merah, kuning, hijau dan biru) dan variasi konsentrasi media dengan penambahan molybdenum (0; 0,01; 0,02; 0,03 mg/L). Hasil penelitan menunjukkan bahwa paparan warna lampu LED biru dan merah menyebabkan meningkatnya kandungan antosianin dan klorofil pada semua media tanaman yang mengandung molibdnum (Mo)., dan sebaliknya dengan peberian paparan warna kuning dan hijau. Kombinasi paparan cahaya lampu LED warna biru dan 0,03 mg/L Mo mampu meningkatkan kandungan antosianin pada daun selada merah mencapai 676,22 µg/g berat segar daun, sehingga dapat digunakan sebagai acuan dalam meningkatkan kualitas selada merah dengan pemilihan warna cahaya dan media tanaman yang optimal.

Black rice (Oryza sativa L. var. Jeliteng), known for its health benefits compared to white rice, faces challenges in productivity. Among varieties, this black rice is popular in Indonesia but shows low yield. Research on improving black rice through genetic manipulation with antimitotic substances is limited. Therefore, this study aims to compare the effects of colchicine and Bio-catharantin on the germination rate, DNA relative content, and stomatal structure of O. sativa L. var. Jeliteng. Seeds were treated with colchicine (0.1%, 0.2%, and 0.3%) and Bio-catharantin (0.1%, 0.2%, 0.3%, 0.4%, and 0.5%) at soaking durations of 12, 24, and 48 hours. Germination was assayed, ploidy was determined using flow cytometry, and stomatal traits, including size and density, were examined microscopically. The results showed that Bio-catharantin did not exhibit any toxic effects on germination rates, whereas colchicine reduced germination starting at 0.2% concentration. Both chemical agents modified the DNA relative content of Jeliteng black rice. Colchicine generally increased stomatal length and width while decreasing stomatal density, with significant changes at 0.3% concentration for 24 hours. Bio-catharantin also altered stomatal traits, enhancing length and width in most cases but significantly reducing density under certain conditions. Bio-catharantin emerged as a promising alternative to colchicine for inducing chromosomal mutations in plants, offering benefits in altered stomatal structures without the toxic effects on germination, compared to colchicine.

Masyarakat pedesaan di Desa Sumberpinang Kabupaten Jember sebagian besar masih memiliki tingkat kesadaran gizi yang kurang. Salah satu solusi untuk meningkatkan gizi masyarakat dalam rangka mengatasi permasalahan tersebut adalah dengan pengenalan inovasi budidaya “wolkaponik” dalam bentuk Taman Sayur Keluarga (Tasya). Sasaran masyarakat yang diberdayakan dan didampingi untuk kegiatan ini adalah ibu-ibu kelompok pengajian “Maslah” (Majelis Silaturahim dan Dakwah), karena ibu-ibu merupakan tonggak penentu pemenuhan gizi keluarga di pedesaan. Kegiatan pemberdayaan masyarakat ini bertujuan untuk: 1). Mendidik masyarakat tentang pentingnya meningkatkan status gizi keluarga; 2). Membekali masyarakat dengan kegiatan Taman Sayur Keluarga (Tasya) berbasis “Wolkaponik”; 3). Membekali masyarakat dengan keahlian budidaya sayur dan ikan untuk meningkatkan produktifitas ibu-ibu kelompok pengajian. Metode pelaksanaan kegiatan yaitu: mengadakan survey dan pemeriksaan kesehatan, dilanjutkan dengan penyuluhan menggunakan metode ceramah dan praktek, pendampingan, serta evaluasi kerberhasilan kegiatan. Hasil yang dicapai dalam kegiatan pemberdayaan masyarakat ini yaitu: (1) peningkatan pengetahuan masyarakat terutama tentang pentingnya pemenuhan kebutuhan gizi anak dan keluarga, (2) peningkatan pengetahuan dan keahlian tentang budidaya “wolkaponik” sebanyak 87%. Program Taman Sayur Keluarga (Tasya) berbasis “wolkaponik”diharapkan dapat mendorong peningkatan konsumsi makanan bergizi berimbang dan untuk membentuk masyarakat mandiri yang mampu berperan aktif dalam kegiatan sosial maupun ekonomi dalam keluarga dan masyarakat.

Background: Metarhizium is one of the entomopathogenic fungi (EPF) that has been widely reported as a useful agent for controlling the coconut rhinoceros beetle (CRB), Oryctes rhinoceros L. (Coleoptera: Scarabaeidae). Application of this fungus as a biopesticide is influenced by regional environmental conditions that affect the pathogenic activity against the targeted pest. Several studies have proven that the native fungal isolates have strong pathogenic activity than EPF introduced from other regions. The identification of local EPF species is a strategic approach to develop potential biopesticides with standard properties including host specificity, climate suitability, and significantly suppressing the target pest population. This study aimed to identify Metarhizium species isolated from infected CRB larvae with high pathogenicity to host pests in East Java, Indonesia. Results: Thirteen isolates were obtained which were divided into 4 clades based on phylogenetic analysis by the ITS rDNA region, namely M. anisopliae var. lepidiotae, M. anisopliae var. anisopliae, M. brunneum, and M. majus. Identified Metarhizium species exhibited varied sizes of conidia, but fell within the size ranges reported in previous studies. Interestingly, the isolate MaSi produced conidial lengths well above the range of conidial sizes recorded and placed these isolates (M. anisopliae) in the MGT clade, known as MALC (M. anisopliae s.l. with large conidia). The present investigation reported that isolates MaLe, MaMa, MaWa, and MaSi produced higher mortality values than other isolates, supporting that M. majus and MALC had higher pathogenicity against O. rhinoceros larvae than other Metarhizium species. Neighbor-joining analysis showed a close resemblance between the isolate MaMa and the strain ARSEF 1946, which was isolated from the CRB. In addition, the isolate MaMa had the highest virulence against O. rhinoceros larval cadaver with a faster lethal time (for 50% mortality). This result indicated a possible relationship between phylogenetic status or DNA sequence polymorphisms with Metarhizium pathogenicity and host specificity. Conclusions: The local species of Metarhizium have been isolated from infected CRB larvae, and M. majus isolates exhibited high pathogenicity against O. rhinoceros larvae. The close similarity of M. majus isolates and CRB-isolated strains suggests a possible relationship between pathogenicity and host specificity with phylogenetic status or DNA sequence polymorphisms.

The critical phase of rice plants on water availability includes the vegetative phase when tillering stage, generative phase 1 at panicle initiation stage and generative phase 2 when booting stage. The lack of water in the vegetative phase and in the generative phase will disturb the growth of rice plants. However, if the water needs are fulfilled immediately, the plants will recover and able to grow normally. The ability of plants to do recovery can be improved through the application of potassium fertilizer. This research aimed to determine the optimum dosage of potassium fertilizer when drought occurs in several critical phases to improve the recovery capability of the rice plant. This experiment used a completely randomized design (CRD) with 2 factors where the first factor was the dosage of potassium fertilizer using KCl fertilizer which was 50 kg/ha, 75 kg/ha, 100 kg/ha and 125 kg/ha. The second factor was the difference in the phase of stress, namely the vegetative phase at the time of tillering, the generative phase 1 at panicle initiation and the generative phase 2 when booting. Each treatment combination was repeated 3 times. Observation variables included Rice grain weight per clump, Proline content, Root Dry Weight, Relative Water Content (RWC) leaves, and Height of plants. The results of the study proved that the best dosage of KCl fertilizer to improve rice recovery ability is 100 kg/ha. Rice plants gripped in the vegetative phase have better recovery capabilities than those gripped in the generative phase.Keywords: Recovery, rice, drought stress and potassium.