KONTRIBUSI KALSIUM PADA PERUBAHAN KARAKTER ANATOMI BIBIT KELAPA SAWIT (Elaeis guineensis Jacq.) TERCEKAM KEKERINGAN

NOVI YULANDA SARI, Eka Tarwaca Susila Putra, S.P., M.P., Ph.D.

2019 | Tesis | MAGISTER AGRONOMI

Penelitian bertujuan untuk (1) mengetahui dampak cekaman kekeringan terhadap perubahan karakter anatomi bibit kelapa sawit, (2) mengetahui apakah pemberian Ca dapat memperkuat kekompakan dan meningkatkan kekuatan struktural jaringan bibit kelapa sawit tercekam kekeringan sehingga tanaman lebih toleran terhadap cekaman kekeringan. Penelitian dilaksanakan pada bulan September 2017– November 2018 di Desa Madurejo, Kecamatan Prambanan, Kabupaten Sleman, dan di Laboratorium Biologi, Fakultas Biologi serta Laboratorium Manajemen Produksi Tanaman, Fakultas Pertanian Universitas Gadjah Mada. Penelitian disusun menggunakan rancangan petak terbagi dengan tiga blok sebagai ulangan, faktor cekaman kekeringan sebagai petak utama dan dosis kalsium (Ca) sebagai anak petak. Petak utama terdiri dari tiga taraf yaitu kapasitas lapang (FTSW 1.00), kekeringan moderat (FTSW 0.35), dan kekeringan berat (FTSW 0.15). Sedangkan anak petak terdiri dari empat dosis Ca yaitu 0.0 g/bibit, 0.04 g/bibit, 0.08 g/bibit, dan 0.12 g/bibit. Pengamatan dilakukan terhadap variabel iklim mikro, karakter fisika dan kimia media tanam, karakter anatomi akar, pelepah daun, dan daun, serta pertumbuhan bibit kelapa sawit pada tahapan pembibitan utama. Data dianalisis menggunakan Analisis Varian (ANOVA) pada level 5%, dan dilanjutkan dengan Duncan’s Multiple Range Test (DMRT) jika hasil analisis varian menunjukkan perbedaan yang nyata antar perlakuan. Hubungan antar variabel pengamatan ditentukan dengan analisis korelasi. Hasil penelitian memberikan informasi bahwa cekaman kekeringan moderat dan berat pada bibit kelapa sawit menyebabkan berkurangnya tebal jaringan hipodermis dan diameter floem akar; berkurangnya panjang dan lebar sel epidermis, tebal jaringan hipodermis, diameter xylem dan floem pelepah daun; berkurangnya panjang sel epidermis atas dan bawah, lebar sel hipodermis atas, panjang sel hipodermis bawah, tebal jaringan mesofil, lebar sel palisade daun dan diameter floem daun. Pemberian Ca pada bibit kelapa sawit tercekam kekeringan mampu memperkuat kekompakan sel dan meningkatkan kekuatan struktural sel pada organ akar, pelepah daun, dan daun. Bibit kelapa sawit mengalami peningkatan diameter xylem dan stele akar serta panjang sel bunga karang daun pada dosis Ca 0.04 g/bibit. Bibit kelapa sawit juga mengalami peningkatan tebal jaringan hipodermis, sklerenkim dan diameter floem akar; panjang dan lebar sel epidermis pelepah; lebar sel hipodermis bawah daun, dan diameter floem daun pada dosis Ca 0.08 g/bibit. Pada dosis Ca 0,12 g/bibit, terjadi peningkatan tebal jaringan hipodermis, sklerenkim, dan korteks akar; serta diameter xylem daun bibit kelapa sawit.

The research objectives were (1) to determine the effects of drought stress on changes in anatomical characters of oil palm seedlings, (2) to find out whether calcium (Ca) able to strengthen cohesiveness and increase the structural strength of organs, so that oil palm seedlings were more tolerant to drought stress. The research was conducted in September 2017 - November 2018 in Madurejo Village, Prambanan District, Sleman Regency; Biology Laboratory, Faculty of Biology; and Crop Production Management Laboratory, Faculty of Agriculture, Gadjah Mada University. The study was arranged in split plot design with three blocks as replications, drought stresses as the main plots and Ca doses as subplots. The main plots consist of three levels, namely field capacity (FTSW 1.00), moderate drought (FTSW 0.35), and heavy drought (FTSW 0.15). Meanwhile, the subplots consist of four Ca doses, namely 0.00g/seedlings, 0.04g/seedlings, 0.08g/seedlings, and 0.12g/seedlings. Observations were done on several variables of micro-climates, physical and chemical characters of the planting media, anatomical characters of root, leaf midribs, and leaves, and the growth of oil palm seedlings at the main nursery stage. Data were analyzed using analysis of variance (ANOVA) at 5% levels, and continued with Duncan's Multiple Range Test (DMRT). The relationships patterns among the variables were determined using correlation analysis. The results showed that moderate and heavy drought stresses in oil palm seedlings causes a decrease in thick hypodermic tissue and root phloem diameter; reduced length and width of epidermal cells, thickness of hypodermic tissue, diameter of xylem and floem of leaf midribs; reduced upper and lower epidermal cell length, upper hypodermic cell width, lower hypodermic cell length, mesophile tissue thickness, leaf palisade cell width, and leaf phloem diameter of leaves. The applications of Ca to oil palm seedlings under drought stresses were able to strengthen cell compactness and increase the structural strength of cells in root organs, leaf midribs, and leaves. Oil palm seedlings have increased roots xylem diameter and stele as well as the length of leaf sponge cells at a dosage of 0.04 g/seed of Ca. Oil palm seedlings also have increased in the thickness of roots hypodermic tissue, scelerenchymal, and phloem diameter; the length and width of the leaf midribs epidermal cells; the width of lower surface of leaves hipodermis cells, and phloem diameter of the leaves at a dosage of 0.08 g/seed of Ca. At a Ca dosage of 0.12 g/seed, there were increased in thickness of roots hypodermic tissue, scelerenchyma, and cortex; and the xylem diameter of the leaves of oil palm seedlings.

Kata Kunci : kelapa sawit; cekaman kekeringan; kalsium; karakter anatomi