Budiarto R, Poerwanto R, Santosa E, Efendi D. 2021. Morphological evaluation and determination keys of 21 citrus genotypes at seedling stage. Biodiversitas 22: 1570-1579. The identification of citrus varieties is generally based on flower, fruit, and mature tree characters. The detailed and comprehensive identification of seedling stage is very limited, therefore present study aimed to identify and distinguish 21 citrus genotypes based on 50 morphological characters of vegetative shoot at seedling stage. Cluster analysis using complete linkage agglomerative method showed broader dissimilarities between C. x limon and C. x microcarpa. Unfortunately, this method was limited to differentiate six genotypes within Citrus reticulata Blanco due to extremely low dissimilarities found. All citrus seedlings have similarities in the forms of habitus, gland spots, arrangement and venation of leaf. The result of PCA determined petiole wing, spine, color, hair and fragrance of leaves as five morphological markers at seedling stage. In addition, there was a positive correlation between spine and leaf pleasant. Moreover, the details of morphological dissimilarities between genotypes were described in arranged determination keys.

Previous studies revealed the impact growing location has on the quantity and quality of essential oils derived from numerous Citrus spp., except on the kaffir lime. This study aims to analyze the relationship shared by agroclimatic variables and soil-plant nutrient status to kaffir lime leaves essential oil yield and main composition. The experiment was conducted between February and April 2019 in four growing locations, namely Bogor (6°36′36″ S, 106°46′47″ E), West Bandung (6°48′12″ S, 107°39′16″ E), Pasuruan (7°45′5″ S, 112°40′6″ E) and Tulungagung (8°6′27″ S, 112°0′35″ E). The highest essential oil yield was obtained from Bogor (1.5%), while the lowest one was from Tulungagung (0.78%). The yield was positively and significantly correlated with the rainfall, soil organic carbon, soil pH, and macronutrient levels, i.e., nitrogen, phosphorus, and magnesium. Citronellal, the major component in metabolites’ profile of kaffir lime leaves essential oils, was significantly affected by the growing location. The absolute content of citronellal was positively and significantly correlated with the actual soil pH and leaf Ca content; furthermore, it negatively correlated with the leaf content of Fe, Mn, Zn, Cu. Pearson correlation analysis also showed (i) a negative significant correlation between the relative percentage of citronellol and annual rainfall intensity; (ii) a negative significant correlation between altitude and relative percentage of caryophyllene, and (iii) a positive significant correlation between the relative percentage of linalool and leaf K content.

Kaffir lime is leaf-oriented minor citrus that required extra attention to study. This study aimed to (i) comparatively analyze the young and mature leaf morpho-ecophysiological characters; and (ii) perform a correlation analysis for revealing the relationship among the physiological characters. Plants were ten one-year-old kaffir lime trees cultured under full sun condition. Leaf size was measured by using a specific allometric model. The Li-6400XT portable photosynthesis system was used to observe the leaf ecophysiological characters. The statistical analysis revealed significant differences in leaf size and physiology as the effect of leaf age. A significant size enlargement in mature leaves was noticed, especially in terms of leaf length, area, and weight, of about 77%, 177%, and 196%, respectively. Young leaves experienced a significant improvement in photosynthetic rate and actual water use efficiency for about 39% and 53%, respectively. Additionally, a strong, significant, and positive correlation between leaf chlorophyll, carotenoid content, and photosynthetic rate was found in the present study. Further studies using a multi-omics approach may enrich the science between kaffir lime leaf maturation as the basis of agricultural modification practice.

Pesik A, EfendiD, NovariantoH, DinartiD, Sudarsono S. 2017. Development of SNAP markers based on nucleotide variability of WRKY genes in coconut and their validation using multiplex PCR. Biodiversitas 18: 465-475. Development of molecular markers benefits coconut breeding program. The availability of DNA sequences for coconuts opens the new possibility of developing molecular markers such as single nucleotide amplified polymorphism (SNAP). The study aimed to evaluate nucleotide sequence diversities of WRKY gene in the GenBank database, design gene specific primers for generating WRKY gene specific SNAP markers, optimize multiplex PCR technique and validate SNAP marker effectiveness for evaluating Kopyor coconut germplasm. Based on 35 sequences data of coconut WRKY genes that are available in the GenBank database, we have identified eight informative SNPs and used them to generate SNP-specific primers. We have designed sixteen primer pairs and validated them using singleplex PCR. Subsequently, we optimized the Ta and primer concentrations either for duplex or triplex PCR. Duplex PCR using two sets of primer pairs was more reliable for genotyping Kopyor coconut germplasm than triplex PCR. We have successfully demonstrated the duplex PCR for genotyping Banten Tall, Jember Tall, Kalianda Tall, Pati Dwarf and Sumenep Tall Kopyor coconuts. Therefore, one may use the developed SNAP markers as a simple alternative of co-dominant markers for genetic analysis of coconuts. One may use the developed SNAP markers to investigate the possible association between markers and Kopyor endosperm and other relevant phenotypes in coconuts.Keywords: Kopyor coconut, multiplex PCR, SNP

Kaffir lime (Citrus hystrix DC) is a minor citrus and its leaves are locally used for spices and essential oils. This study aimed to evaluate agronomical and physiological characters of kaffir lime seedling under modified cultural practices in order to improve leaf production. Shading and pruning were applied on five-month-old seedling during the rainy season, November 2017 to March 2018 in Bogor, Indonesia. The results showed that shading significantly improved the plant growth by 84%, and leaf number by 37%. Pruning treatment reduced the plant height by 8% and increased the shoot number by 20%. However, leaf production was more influenced by shading rather than pruning, with an increase for about 59% than control. This study also revealed a significant improvement on photosynthetic rate, stomatal conductance and water use efficiency on shaded lime for about 13%, 8% and 14%, respectively. Leaf pigment was also altered in response to shading, i.e the increasing chlorophyll B by 23% and the reduction anthocyanin by 38% on shaded lime. Mild shading with 24% light reduction is recommended to gain the leaf production of kaffir lime seedling.

Research papers on horticulture crops, biotechnology, tomato, apple, fruits vegetables, irrigation, water stress, drought resistance, postharvest technology etc