Buletin Kebun Raya

57-70

Authors: Lia Hapsari, Ahmad Masrum

Banana Bunchy Top Disease (BBTD) caused by Banana Bunchy Top Virus (BBTV) is one of the most serious banana diseases, constraint and devastate to the local and regional banana production. Some of banana cultivars were more readily infected by the virus, but considering no cultivars is resistant. The incidences of BBTD and the type and severity symptoms in natural conditions without any artificial inoculation were recorded. The observations results on 2009 showed that 12.14% of the total accessions indicated positively infected BBTD. The BBTD incidences were increased rapidly about twofolds per year, 28.57% in October 2011 and 54.29% in October 2011. The spread and development of BBTD is optimum at humid, high rainfall intensity and temperatures, high soil fertility and also low light intensity or shaded. The latest monitoring on February 2012 (62.14%) comprises of 64 accessions were positively infected and 39 accessions were symptomless. Those symptomless accessions were initially indicated as tolerant banana cultivars to BBTD e.g. Pisang Kepok (BBB), Pisang Sobo (BBB), Pisang Bandung (ABB), Pisang Nangka (AAB), Pisang Candi (AAB) and Pisang Raja Marto (AAB). These preliminary results are in agreement with several previous studies indicated that genotypes with one or two B genomes tend to be more tolerant to BBTD. However several cultivars which known tend to BBTD tolerant are indicated susceptible to Blood Disease. Some cultivars also showing complication symptoms both BBTD and Blood Disease.

81-92

Authors: Andes Hamuraby Rozak

The Family of Magnoliaceae is one of the most primitive taxa in the world. Knowledge of this family is essential for studies on the origin, evolution and systematics of Angiosperms. There are 223 species belongs to this family in the world and 25 of them are found in Indonesia. This paper explains taxonomy, distribution, and conservation status of the family Magnoliaceae in Indonesia.

103-115

Authors: Kartika Ning Tyas, Slamet Susanto, Iswari S Dewi, Nurul Khumaida

Indonesia has high variety of pummelo [Citrus maxima (Burm.) Merr.], but only several cultivar are cultivated extensively. Others became vurnerable and the germplasm has to be conserved to prevent their extinction. One of the conservation method is in vitro conservation using a slow growth technique. Factorial experiment was used in designing the experiment, the first factor was MS medium concentration, i.e. 1/2MS and MS. The second factor was sucrose concentration, i.e. 0; 1; 2; and 3%. The results showed that low concentration of MS medium and sucrose reducing the leaf number and shoot length but increasing the root number and length. Based on inhibition of growth, the most reducing growth was planlet on MS without sucrose.