Induction and Growth of Endosperm Cali of Rimau Gerga Lebong (RGL) Citrus on Several Media Compositions

Rimau Gerga Lebong (RGL) variety is one of the main orange fruit commodities in Lebong Regency of Bengkulu Province, which has a competitive advantage and has good market potential. However, high number of seed characteristic makes this orange fruit becomes less popular. Triploid genotype formation through endosperm culture in vitro is an alternative solution to develop seedless orange fruit. The objective of this study was to determine the best composition medium for callus induction of endosperm of RGL orange seeds as the foremost step of in vitro triploid plant development. The research was conducted from August 2017 until December 2018 at the Plant Tissue Culture Laboratory, Department of Agronomy, Faculty of Agriculture, University of Bengkulu. The experiment was arranged in a completely randomized design, with eight treatment combinations i.e. G1 (MT + 5 ppm BAP + 2 ppm 2,4-D), G2 (MT + 5 ppm BAP + 2 ppm 2,4-D + 500 ppm CH), G3 (MT + 5 ppm BAP + 2 ppm 2,4-D + 500 ppm + 0.5 ppm Kinetin), G4 (MT + 5 ppm BAP + 2 ppm 2,4-D + 500 ppm CH + 0.5 ppm to 500 ppm Kinetin + ME) , G5 (MS + 5 ppm BAP + 2 ppm 2,4-D), G6 (MS + 5 ppm BAP + 2 ppm 2,4-D + 500 ppm CH), G7 (MS + 5 ppm BAP + 2 ppm 2,4- D + 500 ppm CH + 0.5 ppm Kinetin), G8 (MS + 5 ppm BAP + 2 ppm 2,4-D + 500 ppm CH + 0.5 ppm to 500 ppm Kinetin + ME), with three replications. The experimental unit was five culture bottles containing three explants per bottle. Observations were conducted on days to callus formation, rate of callus formation, callus weight, callus diameter, callus color and texture. The results showed that media of MS + 5 ppm BAP + 2 ppm 2,4-D + 500 ppm CH was the best media for callus induction, and MT + 5 ppm BAP + 2 ppm 2,4-D + 500 ppm CH was the best media for callus development.Keyword: RGL citrus, calli, endosperm, kinetin, BAP

PERAKITAN VARIETAS JERUK TANPA BIJI MELALUI PEMULIAAN KONVENSONAL DAN NONKONVENSIONAL

<p>Existence of seeds in the citrus fruit, becomes a major problem that it cannot be received by consumer, even though the fruits has a good taste. Citrus breeders have long been conducting research to improvement of seedless cultivars with the diverse approach. Breeding’s strategies to gain seedless character covering conventional and non-conventional techniques. Conventional technique develop through controlled sexual or interploidi crossing. Seedless character transfer by sexual crossing technique have to do trough manipulate of crossing technique to gain seedless progeny. Crossing technique manipulate through environment manipulation, application of plant growth regulators, parent’s selections and embryo rescue. Non-conventional technique to seedless improvement cover to embryo rescue, endosperm culture, in vitro mutagenesis, inter species and inter ploidi somatic hybridization, cybrid production, and develop of GMO. Current breeding to improve seedless citrus done by ploidy manipulation approach with the target is triploid plant which produce seedless. Indonesian Agency for Agricultural Research and Development- IAARD have succeeded registering varieties of seedless citrus, Pamindo Agrihorti (2016) and SoE86 Agrihorti (2017), which resulted from mutation breeding. Furthermore there are also various line of triploid citrus and citrus obtained through protoplast fusion and being adaptation tested at lowland and highland.</p><p>Keywords: Citrus spp., seedless, plant improvement, conventional, biotechnology</p><p> </p><p><strong>Abstrak</strong></p><p>Jeruk dengan biji yang banyak kurang disukai konsumen meskipun rasanya manis. Para pemulia sudah sejak lama melakukan pemuliaan tanaman jeruk untuk mendapatkan kultivar dengan buah tanpa biji (seedless). Strategi pemuliaan yang dilakukan untuk mendapatkan buah jeruk seedless meliputi penerapan teknik konvensional dan nonkonvensional. Teknik konvensional dikembangkan melalui persilangan seksual terkontrol atau persilangan interploidi. Pemindahan karakter seedless dengan teknik persilangan seksual harus dilakukan dengan memanipulasi teknik persilangan untuk mendapatkan progeni yang berkarakter seedless. Manipulasi teknik persilangan dilakukan dengan modifikasi lingkungan, aplikasi ZPT, pemilihan tetua yang tepat dan penyelamatan embrio. Teknik nonkonvensional yang telah dilakukan dalam pemuliaan jeruk seedless meliputi penyelamatan embrio, kultur endosperma, mutagenesis in vitro, hibridisasi somatik interspesifik dan interploidi, produksi sibrid, serta perakitan tanaman transgenik. Saat ini pemuliaan untuk mendapatkan tanaman jeruk dengan karakter seedless banyak dilakukan melalui pendekatan manipulasi ploidi dengan target diperolehnya tanaman triploid yang akan menghasilkan buah seedless. Balitbangtan sudah berhasil mendaftarkan varietas jeruk tanpa biji, Pamindo Agrihorti (2016) dan SoE86 Agrihorti (2017), yang dihasilkan melalui pemuliaan mutasi. Selain itu juga telah diperoleh beberapa galur jeruk triploid dan jeruk hasil fusiprotoplas yang sedang diujiadaptasikan di dataran rendah dan tinggi.</p><p>Kata kunci: Citrus spp, tanpa biji, perakitan tanaman, konvensional, bioteknologi</p>

Kultur In Vitro Endosperma, Protokol yang Efisien untuk Mendapatkan Tanaman Triploid secara Langsung

<p>In Vitro Culture of Endosperm: An efficient protocol to<br />propagate triploid plants directly. L. Agus Sukamto.<br />Triploid plants are very vigorous and beneficial since they<br />generally produce seedless fruits, bigger flowers, and produce<br />more volume of wood than the diploid counterparts.<br />The triploid plants can be produced by crossing diploid and<br />tetraploid plants, but this method is cumbersome and takes<br />a long time. In vitro culture of endosperm is an alternative<br />method to produce triploid plants directly. The success of<br />endosperm culture is dependent on many factors, such as<br />maturity of endosperm, presence of the zygotic embryo, culture<br />medium, growth regulators, browning, culture period,<br />an plant species. Generally, a mature endosperm needs an<br />initial association with an embryo to induce cell divisions,<br />while proliferation of an immature endosperms is not<br />dependent on the embryo. Endosperm of most parasitic<br />angiosperms shows direct organogenesis without callus<br />formation. Plants produced from endosperm culture are<br />generally triploid, although some plants possess different<br />ploidy levels.</p>