Oil bodies sizes variation analyses of rapeseed in two locations as a novel trait for genetic engineering

Abstract

Abstrak

Tanaman raps (Brassica napus L.) adalah tanaman penghasil minyak utama di negara dengan iklim dingin seperti di Jerman. Minyak raps (Brassica napus L.) digunakan untuk bahan pangan, biodiesel, dan sebagai pakan ternak. Kandungan minyaknya bisa mencapai 33 – 48%. Tanaman  minyak seperti kedelai (Glycine max), raps (Brassica napus L.), bunga matahari (Helianthus annuus) pada umumnya menyimpan kandungan minyaknya dalam suatu organela penyimpanan dikenal dengan ‘oil body’ yang mempunyai  diameter antara 0,6 hingga 2,0 µm, tergantung dari spesies tanaman. Peningkatan kandungan minyak merupakan salah satu target pemuliaan di banyak tanaman minyak, termasuk di raps. Tulisan ini menceritakan tentang isolasi ‘oil body’ dari tanaman raps menggunakan metode sentrifugasi, yang dapat mengurangi efek negatif dari n-heksan sebagai zat ekstraktor yang lazim digunakan dalam proses penyulingan minyak. Sebanyak 200 mg benih B. napus L. kultivar ‘Maplus’ digunakan sebagai bahan dalam penelitian ini. Benih berasal dari populasi Double Haploid (DH) yang ditanam di dua lingkungan yang berbeda secara signifikan di Cina dan Jerman. Rata-rata kandungan minyak dari dua populasi juga berbeda, yaitu 49,18% di Cina, dan 56,94% di Jerman. Dalam penelitian ini, ‘oil body’ diisolasi melalui metode sentrifugasi dan distribusinya diamati di bawah mikroskop cahaya. Berdasarkan pengukuran partikel ‘Coulter Counter’, diameter ‘oil body’ pada tanaman raps bervariasi  antara 1,03 - 1,07 µm (rata-rata= 1,05 µm) pada genotipe dari Jerman, dan 0,98 - 1,02 µm (rata-rata= 1,00 µm) pada genotipe Cina. Selain itu, studi ini mengkonfirmasi korelasi positif dan sangat signifikan antara ukuran ‘oil body’ dengan kandungan minyak di tanaman raps.

Kata Kunci: Coulter Counter, Deutschland, sentrifugasi, tanaman minyak

Abstract

Rapeseed (Brassica napus L.) containing oil content from 33 up to 48% (on 8.5% moisture basis) is the major source of oil plant in many temperate regions, e.g. in Germany. It is mainly applied for cooking, bio-diesels; and animal fodder. Seed plants (soybeen, rapeseed, sunflower) store oil in a storage organelle called oil body whose size varies from 0.6 – 2.0 µm, depending on the plant species. Increasing the oil content is one of the breeding targets in many of oil plants, including in rapeseed. Due to increasing awareness of the environment and the hazardous impact of solvent extraction agents; such as n-hexane (C₆H₁₄) on human health, their application in the oil extraction process is slowly being reduced. A more friendly oil extraction method via centrifugation was introduced over the past decade as well as for biotechnological application. Each 200 mg of B. napus L. cv. ‘Maplus’ seeds were applied as material in this study. Seeds originated from the Double Haploid (DH) population grown in two significantly distinct environments in China and Germany. The average of oil content from two populations was also different, namely 49,18% in China, and 56,94% in Germany. In this study, oil bodies were isolated via the centrifugation method and their distribution was observed under the light microscope. Based on the Coulter Counter measurement, the diameter sizes were ranging from  1,03 - 1,07 µm (mean= 1,05 µm) and 0,98 - 1,02 µm (mean= 1,00 µm) in German and Chinese genotypes, respectively. This study confirms a positive and very highly significant correlation between the size of oil bodies and oil content in rapeseed.

Keywords: centrifuge, Coulter Counter, Deutschland, oil plant