Analisis Pengelompokan dan Hubungan Kekerabatan Spesies Anggrek Phalaenopsis Berdasarkan Kunci Determinasi Fenotipik dan Marka Molekuler RAPD - Dwiatmini, Kristina; Mattjik, N.A; Aswidinnor, H; Touran-Matius, N.L (Jurnal Hortikultura, 2003)
Hubungan kekerabatan antara 19 anggrek phalaenopsis dianalisis menggunakan random amplified polymorphic DNAÂ Â  pada tingkat molekuler dan secara fenotipik menggunakan kunci determinasi dari Sweet. Dendrogram kekerabatan anggrek phalaenopsis tersebut diperoleh dari 300 pola pita DNA dan 27 karakter fenotipik. Hubungan kekerabatan secara genetik dianalisis menggunakan koefisien kemiripan Dice dan jarak genetik secara fenotipik menggunakan koefisien Dist. Korelasi antara keduanya dianalisis menggunakan statistik Mantel dengan prosedur MXCOMP pada program NTSYS. Hasil penelitian menunjukkan hubungan kekerabatan berdasarkan koefisien kemiripan Dice adalah 0,24-0,66 (jarak genetik antara 0,34-0,76), sedangkan jarak taksonomi berdasarkan koefisien Dist adalah 1,42-0,08. Nilai korelasi antara matriks kemiripan dan matriks jarak adalah kecil yaitu -0,38, dengan nilai koefisien determinasi R2Â  = 0,15. Nilai koefisien determinasi yang kecil menunjukkan bahwa hanya 15% data morfologi dapat digunakan untuk mengestimasi kemiripan genetiknya. Hasil analisis komponen utama menunjukkan terdapat 231 pita yang berperan dalam pengelompokan secara terpisah 19 spesies anggrek phalaenopsis, namun tidak dapat mengidentifikasi pita spesifik untuk karakter atau genotip tertentu. Kata kunci : Kunci determinasi; Kekerabatan genetic; Phalaenopsis; Penanda molekuler RAPD; Analisis pengelompokan. ABSTRACT. Genetic relationships among 19 genotypes of phalaenopsis orchid were investigated us- ing random amplified polymorphic DNA technique at the DNA level and using the determination key introduced by sweet at the phenotypical level. Orchid dendrogram was obtained from banding patterns of DNA and from 27 phenotypic traits scored, using Dice similarity and average taxonomic distances respectively. Correlation between a pair of proximity matrices was tested with the Mantel statistic generated by the MXCOMP procedure in NTSYS-pc software. The results showed that constant similarity coefficient and relative order were obtained with 16 primers (300 DNA bands). Genetic relationships among 19 species of phalaenopsis orchids based on Dice similarity coefficient var- ied from 0.24 â 0.66 (genetic distance 0.34 â 0.76). Cluster analysis based on the determination key indicated that the genetic distance (Dist coefficient) varied from 1.42 â 0.08. Grouping of phalaenopsis species using RAPD technique was different from the one using phenotypic characters as used by Sweet with correlation value -0.38 and coefficient determination value 0.15. A small correlation coefficient indicated that the relationship between variables is weak, meaning that average taxonomic distance could not be used to estimate the genetic similarity. The principal compo- nent analysis showed the relative position of 19 genotypes of phalaenopsis in two and three dimensions (principal component). The same procedure also identified the most important DNA bands (231 bands) having very important roles in the grouping, but failed to identify any specific band for any particular character or genotype.