Discrimination of zygotic and nucellar seedlings of citrus rootstocks by isozyme analysis

English. Discrimination of zygotic and nuccellar seedlings is important not only in citrus breeding and development, but also in citrus propagation programs, particularly during the early growth of the seedlings. Isozyme analysis was applied to determine these two genetical seedlings types. The proportion of zygotic seedlings of rough lemon, trifoliata orange, sweet orange and tryoer citrange was very low, this was probably due to the large number of dead seedlings in the nursery before analysis. The zygotic seedlings of cleopatra mandarin could not be detected, because the loci showed by these enzyme systems were homozygous. It was found that the morphological method was able to disseminate only 25 percent of the detectable zygotic seedlings, and therefore it was then concluded that morphological method was less precise than the isozyme method

Indonesian. Diskriminasi bibit sigotik dan nuselar jeruk batang bawah sangat perlu untuk dilakukan, mengingat dua aspek penting dalam industri jeruk baik yang mencakup hal pemuliaan maupun perbanyakan tanaman. Teknik isozime telah berhasil digunakan untuk menganalisis perbedaan tipe genotipe kedua jenis bibit tersebut. Proporsi bibit sigotik dari lima jenis jeruk batang bawah rough lemon, trifolian orange, sweet orange dan troyer citrange adalah sangat kecil. Hal ini disebabkan tingginya angka kematian bibit ketika dipersemaian sehingga lolos dari analisis. Bibit Sigotik jeruk cleopatra mandarin tidak terdeteksi, karena loci yang ditunjukkan oleh enzim tersebut adalah homosigus. Metoda morfologi hanya mampu membedakan 25 persen dari bibit sigotik yang terdeteksi, sehingga dapat disimpulkan bahwa metoda ini mempunyai tingkat ketelitian yang lebih rendah bila dibandingkan dengan metoda isozime