VOLUME 7 NUMBER 2 (July to December 2014)
Phil. Sci. Lett. 2014 7 (2) 387-397
available online: November 25, 2014
*Corresponding author
Email Address: daisymay_constantino@yahoo.com
Submitted: July 31, 2014
Revised: August 26, 2014
Accepted: October 8, 2014
ARTICLE
Molecular and morphological differentiation among Coffea (Rubiaceae) varieties grown in the farms of Cavite Province, Philippines
by Ernelea P. Cao1,2, Daisy May Constantino-Santos*1,2, Lara Anjela P. Ramos1, Brian S. Santos1, Jonas P. Quilang1, and Ruel M. Mojica31Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
2Natural Sciences Research Institute, University of the Philippines, Diliman, Quezon City 1101, Philippines
3National Coffee Research Development and Extension Center, Cavite State University, Indang, Cavite 4122, Philippines
Coffee is a favorite drink of many people around the world. Its genus Coffea is widespread in Africa, Latin America, and Southeast Asia. In this study, three coffee species representing four varieties that are commercially grown in Cavite Province in Southern Luzon, Philippines were studied for molecular and morphological identification and differentiation. These varieties are C. arabica (Arabica coffee), C. canephora (Robusta coffee), C. liberica var. Liberica (Liberica or Barako coffee), and C. liberica var. Dewevrei (Excelsa coffee). Leaf samples were collected from coffee farms in Amadeo town and Tagaytay City in the province of Cavite and from the germplasm collection of the Cavite State University in Indang town also from the province of Cavite. DNAs were extracted and sequenced using matK and rbcL genes. The neighbor-joining trees were generated including other matK and rbcL sequences available in GenBank. Coffea liberica var. Liberica and C. liberica var. Dewevrei from Amadeo, Tagaytay, and Indang consistently clustered together for both matK and rbcL sequences, indicating the genetic homogeneity of the samples. This also supports their reported classification as varieties of one species. While overall, C. arabica sequences clustered together, there is a need to further examine some Arabica and Robusta samples since some samples clustered together. Misidentified seedlings being distributed to coffee farmers may also be a factor. The matK gene compared to rbcL gene served as a better molecular marker for differentiation of the species and varieties in this study. On the other hand, morphological differentiation, using morphometric analyses of leaf width and leaf shape of the different varieties using traditional- and landmark-based methods also showed significant differences among the varieties. MANOVA comparing the leaf shape of all four varieties generated three distinct canonical variates (CV). The CVA plot generated showed C. liberica var. Liberica and C. liberica var. Dewevrei forming distinct groups along the CV1 axis, while C arabica and C. canephora were separated along the CV2 axis. It is interesting to note that although there was no sequence variation in matK and rbcL between the two C. liberica varieties, significant differences were observed morphologically for six of the morphometric characters measured as well as for the landmark-based morphometrics so that the two varieties can be differentiated using these morphological markers. This is the first time that information from molecular data and morphological assessment using morphometrics has been used in studying identification and differentiation of coffee varieties in the country.