Fresh Tuber Yield and Harvest Index Distribution in Segregation Population of Cassava Clones
Kartika Noerwijati, Sholihin, Lulu Husna
Indonesian Legumes and Tuber Crops Research Institute, Malang, Indonesia
Abstract
Background: Conventional breeding to produce new high yielding varieties of cassava still dominates. Germplasm evaluation is the initial stage in conventional breeding, followed by hybridization to increase genetic diversity and clonal selection: single plant selection, single row selection, preliminary tests, and multilocation tests (Mariscal et al. 2001). In some areas, cassava is widely planted in upland dry land (600-1000 m above sea level). In the highlands, cassava requires a longer harvest time (aged 15 months to 24 months) in order to obtain high tuber yields. Noerwijati and Budiono (2015) reported that decreased tuber yield at 530 m asl was 32 %, while at 800 m asl was 86 %, compared to tuber yield at 80 m asl. lrikura et al (1979) have clearly stated that distinct genotypes are required for high altitude (mean temperature less than 22°C) compared to the lowland. Aims: to select high yielding cassava clones for use as selection material for adaptive cassava clones to medium-high altitude. Materials and Methods: The study was conducted in the Jambegede research station, Kepanjen sub-district, Malang, East Java, in 2018 planting season. The materials used in this study include 1016 cassava clones. Single plants from the crossing were planted in the field with a spacing of 100 cm x 80 cm. The design used is Augmented design with control varieties were several cross-parent genotypes, namely UK 1 Agritan, Litbang UK, Malang 4, Adira 4, Lokal Tlekung Ungu, and Gajah Ungu. Plants are fertilized with a dose of 225 kg Urea + 200 kg Phonska + 100 SP 36 per hectare. Fertilizer is given twice, namely 1 month and 3 month after planting. Weeding and repairs of ridges are carried out before fertilization. The parameters observed were fresh tuber yields and harvest index. The data obtained were analyzed using descriptive statistics and cluster analysis. Results: From 1016 individual in F1 cassava populations, have a tuber yield range of 0.20 kg to 9.20 kg with an average of 1.80 kg/plant. The average yield of each F1 family did not exceed the average of the control varieties. This is because the results of tubers in F1 population can not be maximized because the plants come from seeds, there are even F1 plants that do not produce tubers. However, there are F1 individuals that have tuber yield per plant above the average of control variety. The family that had the highest tuber yield per plant was the result of an open pollinated with female parent of the Kaspro clone. For the harvest index, the selected family has a harvest index above 0.5, which means they have good ability to produce tubers. From 1016 F1 individuals have a harvest index range of 0.25 to 0.96 with an average 0.75. These results are shown in the analysis cluster based on data on the average yield of tubers and harvest index of the F1 family which form five clusters. The control varieties form separate clusters from the average F1 family, with characteristics of tuber c
Keywords: cassava, harvest index, segregation, tuber yield. References
Topic: Environmentally Sustainable Agriculture