Morphological, physiological, pests and diseases responses of citrus seedling cultivars, and their contribution to cultivar classification under nursery house and open field

Abstract

Information of morphological, physiological, and pests and diseases traits between Siam or Tangerine (C. nobilis L.) and Keprok or Mandarin (C. sinensis) seedlings group under nursery and open filed condition in Indonesia has limited. The contribution of morphological and physiological characters to cultivar classification of Siam and Mandarin group has also not been yet documented. The aims of this research were to evaluate the morphological, physiological, pests and diseases responses of citrus seedling cultivars, and their contribution to cultivar classification. This research was conducted at Tlekung Experimental Garden, Citrus and Subtropical Fruits Research Institute, Batu, East Java, Indonesia from February to December 2020. One-year-old budded seedlings were planted in plastic bags (size 15x30 cm) and put in both a nursery house and open field.  The plastic bags were filled with mixed media (rice hull, soil, and compost) with the ratio of 1:1:1. The experimental design was a Two Stage Nested Design consisted of two factors, these were factor A: locations (nursery house and open field) and factor B as a nested-on factor A: cultivars (Siam cv. Pontianak, Siam cv. Banjar, Siam cv. Madu, Keprok cv. Kacang, Keprok cv. Terigas, Keprok cv. Madura and Keprok cv. Gayo). The results showed that the highest flush growth percentage was showed by Keprok cv. Madura grown under open field condition, while the biggest rootstock diameter was obtained from Siam cv. Madu grown in nursery house.  Siam cv. Madu grown in open field also produced the highest root dry weight and stomata density. In terms of pests and diseases, aphids (Aphis gossypii) and leaf miner (Phyllocnistis citrella) have only been affected by locations, while for diseases was not found in this study. Contribution of morphological and physiological traits to citrus cultivars classification were about 64.70%. The average percentage of change in growth and develop capacity of Keprok group from open field to the nursery house increased by 2.35%, whereas for Siam one tended to decrease by 8.96%. In general, responses of morphological and/or physiological traits between Siam and mandarin group two locations were varied. Morphological and physiological traits may also useful for supporting genetically evaluation in improving citrus breeding programs.