Dikegulac, a growth regulator, was shown to stimulate in vitro shoot multiplication of olive cultivars Canino, Frantoio, Moraiolo, but not cultivars Rosciola and Piantone di Moiano. The Rugini Olive Medium including zeatin (4.5 lM) was used supplemented with a range of dikegulac concentrations (0-133.4 lM). An optimal result in number of shoots and nodes was obtained on cultivars Canino, Frantoio and Moraiolo at 66.7 lM dikegulac. Higher concentrations did not stimulate additional shoot and node formation and resulted in a drastic reduction in height of shoots. Elongated shoots were rooted and acclimatised and showed normal development compared to control plants.

A non-destructive, simple and accurate model for estimating the individual leaf area of kiwi (Actinidia deliciosa).

Background Natural rubber (cis-1,4-polyioprene, NR) is an indispensable industrial raw material obtained from the Pará rubber tree (H. brasiliensis). Natural rubber cannot be replaced by synthetic rubber compounds because of the superior resilience, elasticity, abrasion resistance, efficient heat dispersion, and impact resistance of NR. In NR production, latex is harvested by periodical tapping of the trunk bark. Ethylene enhances and prolongs latex flow and latex regeneration. Ethephon, which is an ethylene-releasing compound, applied to the trunk before tapping usually results in a 1.5- to 2-fold increase in latex yield. However, intense mechanical damage to bark tissues by excessive tapping and/or over-stimulation with ethephon induces severe oxidative stress in laticifer cells, which often causes tapping panel dryness (TPD) syndrome. To enhance NR production without causing TPD, an improved understanding of the molecular mechanism of the ethylene response in the Pará rubber tree is required. Therefore, we investigated gene expression in response to ethephon treatment using Pará rubber tree seedlings as a model system. Results After ethephon treatment, 3270 genes showed significant differences in expression compared with the mock treatment. Genes associated with carotenoids, flavonoids, and abscisic acid biosynthesis were significantly upregulated by ethephon treatment, which might contribute to an increase in latex flow. Genes associated with secondary cell wall formation were downregulated, which might be because of the reduced sugar supply. Given that sucrose is an important molecule for NR production, a trade-off may arise between NR production and cell wall formation for plant growth and for wound healing at the tapping panel. Conclusions Dynamic changes in gene expression occur specifically in response to ethephon treatment. Certain genes identified may potentially contribute to latex production or TPD suppression. These data provide valuable information to understand the mechanism of ethylene stimulation, and will contribute to improved management practices and/or molecular breeding to attain higher yields of latex from Pará rubber trees.

The availability of high-quality seeds is now a necessity. This is due to a government program to replace oil palm trees in smallholder plantations with high quality seeds. An efficient protocol to produce a large number of embryos is needed. To increase the number of embryogenic callus production, the callus proliferation experiment was carried out through suspension culture. This study aimed to examine the proliferation ability of embryogenic callus from three different oil palm clones, in several repeated subcultures. Liquid MS media added with 1 ppm 2.4-D and 0.1 ppm NAA were used. Embryogenic callus was weighed by 0.1 - 0.2 g, transferred into the liquid media, shaking at 60-80 rpm and 27 ºC for 8 weeks without light. Continues subcultures were repeated up to 7 times. The results showed that the growth rate of embryogenic callus increased in the third and fourth subcultures and then decreased in subsequent subcultures. It also revealed that the entire embryogenic callus from the first subculture up to seventh subculture still has the ability to regenerate into new plants. These results indicate that oil palm embryogenic callus can be proliferated by suspension culture with a limit up to the fourth subculture. Ketersediaan benih kelapa sawit berkualitas saat ini merupakan kebutuhan karena adanya program pemerintah untuk menggantikan tanaman sawit di kebun-kebun petani. Salah satu cara vegetatif yang dapat dilakukan adalah meningkatkan jumlah kalus embriogenik yang dihasilkan melalui pengembangan kultur suspensi. Penelitian ini bertujuan mengkaji kemampuan proliferasi kalus embriogenik dari tiga klon kelapa sawit, pada beberapa kali subkultur yang berulang. Media cair MS dengan penambahan 1 ppm 2,4-D dan 0,1 ppm NAA digunakan untuk memperbanyak 0,1–0,2 g kalus embriogenik, dikocok pada 60-80 rpm dan suhu 27 ºC tanpa cahaya selama 8 minggu. Subkultur berulang dilakukan hingga 7 kali. Hasil percobaan menunjukkan bahwa kemampuan proliferasi kalus dipengaruhi oleh genotip tanaman induk. Rata-rata kalus embriogenik dapat meningkat pada subkultur ke-3 dan ke-4 dan semakin menurun pada subkultur selanjutnya. Kalus embriogenik hasil proliferasi subkultur pertama hingga ke-7 dapat tumbuh menjadi calon tanaman baru. Hasil ini menunjukkan bahwa kalus embriogenik kelapa sawit dapat diperbanyak dengan kultur suspensi pada batas sampai subkultur ke-4.

Bio-SRF is a biofertilizer formulation containing a mixture of several types of microbes improving soil fertility. The aims of this study were to assess the production process of Bio-SRF biofertilizer and to identify its effectivity on Keywords: Biofertilizer, Bio-SRF, production process, effectivity test, shallot plant ABSTRAKBio-SRF merupakan formula produk pupuk hayati yang mengandung campuran beberapa jenis mikroba penyubur tanah. Penelitian ini bertujuan untuk mengkaji proses produksi pupuk hayati Bio-SRF dan mengetahui efektivitasnya terhadap pertumbuhan dan produktivitas tanaman bawang merah. Kajian produksi pupuk hayati Bio-SRF meliputi perbanyakan biomassa sel mikroba, granulasi dan formulasi produk. Hasil penelitian menunjukkan bahwa populasi sel pada produk pupuk hayati Bio-SRF bentuk granul adalah Corynebacterium sp. 4  10 7 cfu/g, Lactobacillus sp. 3,8  10 7 cfu/g, Burkholderia seminalis 7,4  10 8 cfu/g, Pseudomonas stutzeri 4,5  10 8 cfu/g dan mikoriza 60 spora/g produk. Hasil uji efektivitas menunjukkan bahwa perlakuan pupuk hayati berpengaruh nyata terhadap tinggi tanaman, jumlah umbi, bobot basah dan bobot kering umbi bawang merah yang dihasilkan. Aplikasi pupuk hayati Bio-SRF pada tanaman bawang merah memberikan hasil terbaik yaitu dengan tinggi tanaman saat panen 34,80 cm, jumlah umbi per tanaman 4,78 umbi, berat basah umbi 3,81 kg/m 2 , berat kering umbi 3,27 kg/m 2 dan dapat meningkatkan hasil produksi bawang merah sebesar 55,71% dibandingkan dengan tanpa aplikasi pupuk hayati.Kata kunci: Pupuk hayati, Bio-SRF, proses produksi, uji efektivitas, bawang merah