Tri Handayani

Induction and characterization of autotetraploid Mas Jambe Banana using oryzalin treatment

Triploid banana breeding could be achieved by crossing tetraploid to improved diploid banana genotypes. The availability of tetraploid bananas is naturally very limited. One of methods to produce tetraploid bananas is inducing tetraploid plants using chemicals that inhibit spindle fiber formation during mitosis such as oryzalin or colchicines. The present study selects and characterizes autotetraploid Mas Jambe Banana (Musa, AAAA) induced by in vitro oryzalin treatment that will be used as 2n gamete donors in crosses with improved diploids to generate secondary triploids. In vitro–cultured shoots of Mas Jambe Banana parthenocarpic diploid banana (Musa AA) were treated with oryzalin at a concentration of 60μM for 7 days in a liquid MS basal medium with addition of 2 mg/l BA. Ploidy identification of induced Mas Jambe Banana was conducted using a flow cytometer. Forty-two plants were evaluated, of which 24 were autotetraploids. Compared with the original diploids, the Mas Jambe Banana autotetraploids showed significant increases in pseudo-stem height and diameter, fruit size, and bunch weight. The autotetraploid plants exhibited useful agronomic traits and can therefore be used as 2n gamete donors for generating secondary triploids. Keyword: Mas Jambe Banana, pseudo-stem, triploid banana, oryzalin

Mathematics and statistics related studies in Indonesia using co-authorship network analysis

Indonesian scholars have published a numbers of articles in numerous international publications, however, it still lags behind other Singapore, Malaysia, and Vietnam. This article performs a bibliometrics analysis and examine the collaboration network in Mathematics and Statistics related subject of scholars with Indonesian affiliation as recorded in Web of Science. In total, based on article publications during 2009-2017, 426 articles were retrieved. Bandung Institute of Technology ( ITB) was the affiliation with the highest number of articles (48%) and number of authors (27%). Using Social Network Analysis to examine co-authorship networks, this research shows that the co-author network has the highest centrality in the ITB affiliation. Meanwhile, dependency of foreign affiliation is still high, shown as a high percentage (84% of all articles) of international co-authorship. Co-authorship network of Mathematics and Statistics related studies in Indonesia possesses as a scale-free network and followed the power law distribution. This research showed the achievement of Indonesian scholars of Mathematics and Statistics, and can be used to evaluate the knowledge transfer in these subjects and related areas.

Induksi Tetraploid pada Tanaman Jambu Biji Merah (Psidium Guajava L.) secara In Vitro

Some commercial varieties of Guava seedless are triploid and rarely found naturally. A triploid variety with less seeds and better yield potential can be achieved by crossing tetraploid to diploid variety. Guava tetraploid plants can be synthetically induced by using oryzalin or colchicine to double the chromosome from its diploid. This research was aimed to obtain tetraploid lines by studying the effects of oryzalin in germination and in vitro growth of Guava. Seed from Red Guava were cultured in liquid medium MS + 2 mgL-1 BA with adding oryzalin according to the treatment, then seed planted in MS solid medium. Seed explants were exposed to Oryzalin 0 (controls), 15, 30 dan 60 ?M with exposure time are 23, 36 and 49 days or 3, 5, and 7 weeks. Results from polyploid induction were 8 tetraploid (5.48%) and 9 (6.16%) mixoploid shoots in vitro. High est tetraploid shoots were obtained from treatments by exposing the seed explant to 15 – 30 ?M oryzalin for 23 – 36 days. Oryzalin treatments inhibit germination and in vitro growth of Guava until 1st subculture. After second subculture, tetraploid or mixoploid shoots quantitatively showed no difference respons on in vitro growth with its diploid.

STUDI PERILAKU PERKECAMBAHAN BIJI DAN MORFOLOGI PERTUMBUHAN SEMAI KENANGA ( Cananga odorata (Lam) Hook.f.et.Thomson)

Cananga (Cananga odorata) belongs to Annonaceae family. It is potentially used for many purposes, such as for ornamental plant, roadside tree, and timber tree, or as an important component in traditional medicines, traditional ceremonies and the production of some perfumes and biopesticides. As a part of promoting the species conservation and utilization, a study on seed germination of Cananga was carried out in the Bogor Botanic Gardens to observe the viability, germination characteristics and seedling morphology of seeds collected from the Bogor Botanic Gardens plant collection. As many as 450 mature seeds of Cananga were directly sown in three germination beds containing sand medium for germination capacity observation and the other 50 seeds were sown in a separate bed for germinant growth observation. It was noted that seedling emergence of Cananga started at 24 days after sowing and terminated at 45 days after sowing. The total seed germination was 58.05 %. Seedling emergence of Cananga odorata follows an epigeal pattern that shows the leafy emergent cotyledons.