Genetic variability in apomictic mangosteen (Garcinia mangostana) and its close relatives (Garcinia spp.) based on ISSR markers

Abstract. In order to reveal phylogenetic relationship of mangosteen and several close relatives (Garcinia spp.), we employed seven ISSR dinucleotide primer systems on eleven close relatives of mangosteen and 28 mangosteen accessions from four islands in Indonesia (Sumatra, Java, Kalimantan and Lombok). ISSR analysis successfully amplified 43 bands on average 6.1 fragments for each primer system, and these all fragments were polymorphic. Seven close relatives of mangosteen were separated with mangosteen accessions at 0.22 level of dissimilarity, while other four including G. malaccensis, were clustered with mangosteen accessions, this results supported proposal that G. malaccensis was allopolyploid derivative of mangosteen. Clustering pattern among mangosteen accessions, however, not represented their origin, indicated that distribution of the accessions was not linked to their genetic properties.

Key words: Garcinia spp., ISSR analysis, genetic diversity.


Screening of pepper accessions for resistance against two thrips species (Frankliniella occidentalis and Thrips parvispinus)

Abstract. Thrips are damaging pests in pepper worldwide. They can cause damage directly by feeding on leaves, fruits or flowers, and also indirectly by transferring viruses, especially tomato spotted wilt virus (TSWV). Although thrips are among the most damaging pests in pepper, until now there is no commercial variety with a useful level of resistance to thrips. This is at least partly due to the lack of knowledge on resistance levels in pepper germplasm of QTLs and/or genes for resistance, and of information about resistance mechanisms to thrips in pepper. This paper describes our research aimed at developing practical and reliable screening methods for thrips resistance in pepper and at identifying pepper accessions showing a strong resistance to thrips. Thirty-two pepper accessions from four species of pepper (Capsicum annuum, C. baccatum, C. chinense and C. frutescens) and two species of thrips (Frankliniella occidentalis and Thrips parvispinus) were used in this study. Our results indicate that the laboratory based leaf disc test and the detached leaf test can be used as reliable screening methods for thrips resistance in pepper. We observed a large variation for resistance to thrips in Capsicum that can be exploited in breeding programs.

Keywords:  Capsicum  In vitro test  Multiple resistance  Insect resistance


Application of Starter Solution Increased Yields of Chili Pepper (Capsicum annuum L.)

Abstract. Chili pepper (Capsicum annuum L.) was grown with polyethylene mulched on Inceptisol soil with low pH (5.5), low organic-C (1.54%), very low total N (0.12%), low K content (0.29 me (100 g)-1), but very high soil P2O5 concentration (19.2 ppm) to evaluate the best crop management practices with starter solution. Seven starter solution combinations (1 = No Starter Solution + No CM + No SI, 2 = CM + SSVC, 3 = CM + SSG, 4 = SI + SSVC, 5 = SI + SSG, 6 = SI + CM+ SSVC, and 7 = SI + CM + SSG) were arranged in a randomized completely block design with four replications. Whereas CM = cow manure, SSVC = organic starter solution, SSG = inorganic starter solution, and SI=standard inorganic fertilizer. The results showed that inorganic, as well as organic, starter solution increased chili pepper growth and yield in less fertile soil. The highest marketable yield was obtained with application of standard inorganic (SI) + cow manure (CM) + inorganic starter solution (SSG). Inorganic starter solution application resulted in a better plant growth than organic starter solution, being evident at 1 week until 7 weeks after transplanting. However, inorganic starter solution did not signifi cantly increase total marketable yields. Application of cow manure, standard inorganic fertilizer, or addition of organic starter solution reduced total unmarketable yield, improved fruit qualities and increased marketable yield.

Keywords: cow manure, crop management, fertilization, liquid fertilizer, vermi-composting


Perbanyakan Tunas Mikro pada Beberapa Umur Simpan Umbi dan Pembentukan Umbi Mikro Bawang Merah pada Dua Suhu Ruang Kultur

Abstrak. Umbi bawang merah pada umumnya disimpan selama beberapa bulan sebelum ditanam.  Umur eksplan merupakan  salah satu faktor penting yang memengaruhi pertumbuhan tunas in vitro. Suhu ruang kultur dapat mempengaruhi kemampuan  tunas mikro membentuk umbi mikro. Penelitian ini terdiri atas dua percobaan yang bertujuan untuk mengevaluasi 1) pengaruh  umur simpan umbi terhadap pertumbuhan tunas mikro secara in vitro dan 2) pengaruh suhu ruang kultur terhadap induksi  umbi mikro bawang merah.  Pada percobaan pertama, umbi bawang merah untuk keperluan penelitian ini telah disimpan  selama 1, 2, 3 dan 4 bulan sebelum digunakan sebagai eksplan. Umur eksplan nyata memengaruhi pertumbuhan kultur. Umbi yang disimpan selama dua bulan menghasilkan jumlah daun dan akar terbanyak serta tunas vitrous terendah. Tunas mikro berumur tiga minggu dapat digunakan sebagai propagul untuk diinduksi menjadi umbi lapis mikro. Pada percobaan kedua, tunas mikro yang berasal dari media perbanyakan ditanam ke media pengumbian dan diletakkan  di  dua  growth chamber,  masing-masing  dengan  suhu  (siang/malam)  20/17 oC dan 30/27 oC.  Induksi umbi lapis mikro bawang merah dipengaruhi oleh suhu ruang kultur. Suhu rendah meningkatkan jumlah tunas, panjang tunas, jumlah akar dan panjang akar. Suhu 30/27 oC menghasilkan jumlah umbi lapis mikro bawang merah terbanyak, diameter umbi tertinggi, dan rasio diameter terlebar:pangkal umbi yang lebih tinggi dibanding pada suhu 20/17 oC.

Kata kunci: Allium, multiplikasi tunas, suhu, umur eksplan, 2ip