Gall Rust Disease Research Articles

Changes in anatomical characteristics of Falcataria moluccana wood due to Uromycladium tepperianum infection

Serious problems have occurred on Falcataria moluccana plantations because of gall rust disease caused by Uromycladium tepperianum. The disease inhibits tree growth, reduces wood quality, and can cause tree mortality. The presence of galls is a notable symptom of this disease. The study aimed to investigate the anatomy of the galls and the changes in wood anatomical characteristics of F. moluccana due to the infection of U. tepperianum. Wood blocks containing outer bark, cambium and xylem with different levels of severity of gall rust attack were removed from the main stem of F. moluccana trees. Microscopic observations were conducted to observe the anatomical characteristics of the galls, affected wood and healthy wood. The results showed that the anatomy of galls was different from that of affected wood or healthy wood. The percentage of vessel area, diameter of vessel, percentage of ray parenchyma and the length of wood fibres were significantly different between normal wood and affected wood. The results could be useful in understanding gall formation and assessing its impact on wood quality.

Single Nucleotide Polymorphisms (SNPs) Analysis of Resistant and Susceptible Sengon (Falcataria falcata) Accessions to Gall Rust Disease

Single Nucleotide Polymorphisms (SNPs) Analysis of Resistant and Susceptible Sengon (Falcataria falcata) Accessions to Gall Rust Disease

Early boosting of genetically improved Falcataria moluccana with mycorrhiza for better growth and disease tolerance

Falcataria moluccana is a widespread species that grows rapidly in Indonesia and produces timber used for carpentry. Nonetheless, this species is especially susceptible to gall rust disease. To find plants that can handle rust, a mix of breeding with progeny experiments and forest management methods, like arbuscular mycorrhiza (AM), were used. The point of this study is to find out if adding AM changes how F. moluccana seedlings grow and how they react to gall rust disease, both those that have been improved and those that have not. We will also look at the response by calculating the area under disease progress curves (AUDPC) value for rust disease to grow in F. moluccana seedlings. The experimental design comprised four different treatments, including varying quantities of mycorrhizae, as well as four different seed sources. For the mycorrhizal inoculation experiments, there was a control group and three treatment groups. The treatment groups got 5, 10, and 15 g of mycorrhiza per polybag, respectively. The seeds used in this study were sourced from two unimproved families, namely Java and Solomon, as well as two genetically improved families, F63 and F77. This study revealed that mycorrhizal application affects the growth of F. moluccana seedlings and significantly reduces both disease incidence and severity. The application of mycorrhiza reduces the disease incidence and severity; the AUPDC value of seedlings with mycorrhiza added is four times lower than that of seedlings without mycorrhiza. The disease severity was highest for the unimproved Solomon seedlings, despite the fact that the source of seeds had little impact on the disease incidence. Meanwhile, the genetically improved seedlings demonstrated lower disease incidence and severity rates than seedlings without improvement, with an AUPDC value nearly half that of the unimproved seedling. In terms of diameter and height, F. mollucana seedlings derived from various seed sources were remarkably diverse, and seedlings with improvements grew much better than seedlings without improvements. This study shows how arbuscular mycorrhiza affects how well improved and unimproved F. moluccana seedlings deal with gall rust disease.

Development of Few Significant SNP Markers from Transcriptomic Data for Selection of Sengon (Falcataria falcata (L.) Greuter & R. Rankin) Resistant to Boktor Stem Borer and Gall Rust Disease

Sengon (Falcataria falcata (L.) Greuter & R. Rankin) plantations in Indonesia are threatened by attacks from Boktor stem borers and gall rust disease. Controlling pests and diseases is difficult; therefore, planting resistant trees obtained from tree selection programs is necessary. Currently, genomic breeding often incorporates GWAS, which uses thousands of SNP markers to identify markers with significant associations with the traits studied. This study aimed to bypass such expensive studies by identifying and developing SNP markers from sequences of putative resistance genes to Boktor stem borer and gall rust disease, identified from sengon transcriptomic data analysis. A total of 496,194 putative SNP sites were identified from transcriptomic sequences using the SAMtools and BFCtools programs, of which 119 SNP sites were associated with resistance genes. Of the 101 non-synonymous SNPs selected, only 12 were located in the conserved domain of each gene and were used for primer design. Of the 13 primers designed, only 10 were successfully amplified. Validation of 10 developed SNP markers on 100 sengon accessions using the HRM method confirmed a significant association between SNP markers and resistance traits, with a -log 10 (P-value) between 10.49 and 16.63. A few SNPs markers developed from putative resistance gene sequences are associated with resistance traits in sengon. Therefore, the SNP markers could be applied in selection programs for sengon trees resistant to Boktor stem borers and gall rust disease.

Chloroplast genome draft assembly of Falcataria moluccana using hybrid sequencing technology

ObjectivesFalcataria moluccana, known locally as Sengon, is a fast-growing legume tree that is commonly planted in community forests of Java Island, Indonesia. However, the plantations face attacks of Boktor stem borer (Xystrocera festiva) and gall-rust disease (Uromycladium falcatariae) as major threats to its productivity. To control those pest and disease, it is necessary to grow resistant sengon clones, which are developed through tree improvement program, of which needs genetic and genomic information. This dataset was created to construct draft of sengon chloroplast genome and to study the evolution of sengon based on matK and rbcL barcode genes.Data descriptionGenomic DNA was extracted from leaf samples of one individual healthy tree in a private plantation. The DNA was sequenced using Illumina Novaseq 6000 (Novogen AIT, Singapore) for short-reads data, and MinION of Nanopore following manufacture’s protocols SQK-LSK110 for long-reads data. The 66,3 Gb short-reads and 12 Gb long-reads data were hybrid assembled and used to construct a 128.867 bp of F. moluccana chloroplast genome with a quadripartite structure, containing a pair of inverted repeats, a large single-copy and a small single-copy region. Phylogenetic tree constructed using matK and rbcL showed monophyletic origin of F. moluccana and other legume trees.

Isolation and identification of fungi associated with Falcataria moluccana gall-rust in Kediri, East Java, Indonesia

Abstract. Istikorini Y, Cahyani NN, Haneda NF, Shabrina H, Nugroho A, Indriani F, Siregar UJ. 2022. Isolation and identification of fungi associated with Falcataria moluccana gall-rust in Kediri, East Java, Indonesia. Biodiversitas 23: 6171-6179. Gall-rust disease caused by Uromycladium falcatariae is the most important disease of sengon in Indonesia. Plant pathogenic parasitism as a biological control mechanism is usually associated with fungal biocontrol agents. This study aimed to isolate and identify the fungi associated with the sengon gall rust from the Forest Management Unit of Jatirejo, Indonesian State Forest Company, Kediri. Fungi were isolated from the black or gray-green patches of gall-rust samples on Potato Dextrose Agar (PDA) plates. The fungi were identified using macroscopic and microscopic examinations. The molecular identification of fungal DNA was amplified by PCR using a specific internal transcribed spacer primer (ITS1/ITS4). The PCR products were sequenced and compared with the other related sequences in GenBank (NCBI). DNA barcode identification results showed 9 isolates containing of 8 species, namely Fusarium oxysporum, F. solani, F. chlamydosporum, F. circinatum, F. incarnatum, F. verticillioides, Lasiodiplodia theobromae, and Pestalotiopsis palmarum. This result showed that the Fusarium was the most fungi commonly found fungi on the gall's rust teliospore surface.

Diversity of Endomycorrhizas in Falcataria moluccana (Miq.) Barneby & J.W. Grimes Affected by Gall Rust Disease in Laguna, Philippines

Endomycorrhizas or arbuscular mycorrhizal fungi (AMF) are microfungal associates known to facilitate nutrient absorption in higher plants that benefit growth and survival. Studies have shown that they can induce systemic host resistance against pathogenic fungi, but little information is known about its contributions to gall rust disease in Falcataria moluccana, an important plantation tree species. This paper investigated the community of endomycorrhizas under F. moluccana stand affected by Uromycladium rust from a secondary-growth forest in Laguna, Philippines. Three transects (1.5 km) were established wherein matured F. moluccana trees (n = 32) were assessed for gall rust incidence and disease severity index (DSI) using a five-point rating scale to categorize infection. Composite rhizosphere samples were collected from nine sampling plots for macronutrient analysis and AMF assessment. Endomycorrhizal spores were isolated from dissolved 100-g soil solution following wet-sieving and decanting method then characterized morphologically for identification, spore density, and diversity analysis. Results of the tree health survey showed 100% disease incidence with moderate infection (DSI = 30–44). Overall, 13 morphospecies of endomycorrhizal fungi were identified from three orders and five families. The eight genera associated with F. moluccana were Acaulospora, Ambispora, Diversispora, Enthrophospora, Funneliformis, Gigaspora, Glomus, and Rhizophagus. The Shannon diversity index (H’) revealed a significant (p< 0.002) difference in all sites [F (2, 31) = 7.46]. The findings suggest that species abundance and density of AMF fungi are related to soil phosphorous and the severity of gall rust. This study presents the potential of important AMF species for the integrated management of gall rust disease affecting F. moluccana.

Integrated disease management to control gall rust disease on the seedling and sapling of Falcataria moluccana

Several control methods have been developed to control the disease caused by Uromycladium falcatariae. However, it is still used a single approach that may not receive satisfactory results. This study applied integrated disease management that consisted of physical, chemical, and biological approaches to reduce gall rust disease incidence. In the nursery, the control methods used were selecting nursery location, applying the biological agent Trichoderma sp, and regular spraying with fungicides. Meanwhile, after planting, the control methods used were regularly spraying with fungicides, pruning the infected tissues, and fertilizer application. Three active ingredients were used for fungicide application: tebuconazole, a mixture of azoxystrobin and difenoconazole, and tribasic copper sulfate. The result showed no gall rust disease incidence in the seedling until it was ready for planting (4 months old). In addition, the application also gave positive results on seedling growth performance compared to the control. After planting, the incidence of gall rust disease can be reduced between 16.5-32.5% when the saplings were three months old and 14.3-26.3% when the saplings were ten months old. Fungicide with the active ingredient, a mixture of azoxystrobin and difenoconazole, showed more effective protection against gall rust disease infection compared to other active ingredients.

Estimation of heritability in three months old sengon (Falcataria moluccana) seedlings at a progeny testing in Kediri, East Jawa, Indonesia

Heritability values were estimated for three months old seedlings height and diameter of Sengon (Falcataria moluccana) grown in a progeny testing in Kediri, East Jawa, Indonesia. Totally 10.000 seedlings from 100 families were planted, consisting of 50 families from resistant mother trees to boktor pest (Xystrocera festiva) and gall rust disease (Uromycladium falcatariae) and other 50 families from susceptible ones. The progeny testing applied split-plot block design with four blocks, 100 families as sub-plot and resistance to pest and disease as main-plot, while observingnine seedlings as replications. Parameters observed were seedlings height and diameter. ANOVA showed that all treatments had significant and highly significant effects on all parameters. Interactions between block and families also interaction between block and resistance were highly significant. However, the heritability values of height and diameter were both low. These low heritability values at seedling stage were expected as Sengon woods are usually harvested at the age of 5 years. However, the highly significant effects of families on both growth parameters indicated that genetics have high contribution to the seedlings performances in the field.

Pests and diseases on Falcataria moluccana trees in agroforestry systems with pineapple in East Java, Indonesia

Abstract. Rahayu S, Triyogo A, Widyastuti SM, Musyafa’, Ardianyah F. 2021. Pests and diseases on Falcataria moluccana trees in agroforestry systems with pineapple in East Java, Indonesia. Biodiversitas 22: 2779-2788. The agroforestry system using Falcataria moluccana (Sengon) and Ananas comosus (pineapple) is considered as a profitable intercropping system in Indonesia. To make it viable, it is necessary to evaluate the effect of mixed cropping on the incidence and severity of diseases and pests on Sengon trees and apply management measures. The present study was conducted (i) to assess the pest and disease problems on Sengon trees in the agroforestry system and (ii) to identify the most harmful pathogen/pest which affects the growth and causes mortality of Sengon trees at the beginning of intercropping and after the removal of pineapple from the system. Incidence of pests and diseases were assessed in 3 replicate blocks with one-year-old Sengon trees mixed with pineapple, and in another 3 plots with four-year-old Sengon trees from where pineapple was removed after harvesting. Sengon and pineapple were planted in the plots using alley cropping method with 3 x 4 m2 spacing. The results showed that there were no significant pest and disease problems on pineapple. However, Sengon was infested by the white grub Lepidiota stigma, gall rust caused by the fungus Uromycladium falcatarium, the stem borer Xystrocera festiva, and mistletoe Scurrula sp. However, stem borer and gall rust were the only pest and disease issues recorded in the monocultures of Sengon in Indonesia. The occurrence of stem borer and gall rust disease had a significant effect on the diameter growth of trees and in some instances, these caused mortality of one-year-old trees. Significant mortality of four-year-old trees was caused by mistletoe infestation only. Although the incidence of gall rust and stem borer in the agroforestry system was not significantly low compared to the monoculture, the former had wider spacing between trees, more open canopy and resultant low humidity and faster wind speed reduced the severity of the gall rust disease and stem borer attack. However, the intercropping resulted in the white grub attack on young Sengon trees which calls for application of contaminant-free fertilizers in pineapple plantings.

THE EFFECT OF MYCORRIZA TO THE INCREASE OF PLANT HEIGHT AND STEM DIAMETER OF SENGON FROM VARIOUS SEED SOURCES

The purpose of this study was to determine the effect of sengon breed stock and mycorrhiza in increasing plant height and stem diameter. This research was conducted from April 2019 to September 2019 at the Center for Research and Development of Biotechnology and Forest Plant Development in Yogyakarta. Two-factor complete randomized design with 3 replications were used in this study. First factor is seed source, namely I1 = 1-1-63-1, I2 = 1-8-77-4, I3 = Malang (Bulk), and I4 = Solomon (Bulk) and second factor is the dose of mycorrhiza, namely M0 = without mycorrhiza, M 1 = mycorrhiza 5 g/plant, M2 = mycorrhiza 10 g/plant, M3 = mycorrhiza 15 g/plant. Plant height and stem diameter were collected for data. Variance analysis (ANOVA) were used at α level 5% and continued with Duncan's Multiple Range Test (DMRT) at α level 5%. The results of the study showed interactions on combinations that were in line with mycorrhiza doses on plants height and stem diameter of 8 week after planting. Parent 1- 8-77-4 gives the best results on plants height. Seed source 1-8-77-4, 1-1-63-1, and Solomon (Bulk) gives the best stem diameter results. Mycorrhizae can increase plant growth in terms of plant height and diameter.Keyword: mycorrhizae, gall rust disease, Sengon.

Growth performance of Falcataria moluccana in the mixed cropping pattern and its severity from Gall-rust disease: A case study in Ciamis, West Java

Monoculture Falcataria moluccana plantation managed by local communities in Ciamis – West Java, is facing a gall-rust disease caused by fungal pathogen Uromycladium tepperianum. A mixed planting crops system is considered less vulnerable to pests and disease problems. In addition, it is possible to increase the productivity of community forest plantations. This study was aimed to evaluate the effects of mixed-crops plantation on the productivity of F. moluccana and the incidence and severity of gall-rust in the plantation. Then it will be compared to the existed monoculture F. moluccana plantation in the area, that was established two years before. The mixed-crop consisted of F. moluccana, Acacia mangium, and Gmelina arborea. These were alternately planted in three different rows with three replications. The observations of growth increments as well as incidence and severity of gall-rust were carried out in 1.5 years after planting. The results showed that the annual height- and diameter- increments of F. moluccana in the mixed-crop plot were 331.2 cm and 2.77 cm, respectively. Meanwhile, the results in the monoculture plot were 325.62 cm and 2.64 cm. The survival rates of F. moluccana in both planting patterns were slightly different (85.3% and 88%). Gall-rust incidence and severity were only observed in the F. moluccana monoculture plot, i.e., 0.15% and 0.48%, respectively. The mixed-planting crops system seems possible to be applied for controlling the gall-rust disease that attacked the F. moluccana stands. Further research on comparing the similar ages of mono- and mixed- cultures of F. moluccana in different locations were suggested.

PENGENDALIAN PENYAKIT KARAT PURU PADA BIBIT SENGON (Falcataria moluccana) DENGAN PRIMING BENIH DAN FUNGISIDA NABATI DAUN MINDI (Melia azedarach)

Production of sengon continuously improved to meet the needs of the timber industry, but increased production sengon still face the problem of that disease gall rust fungus Uromycladiumtepperianum Sacc. that is causing inhibited growth of sengon, so it needs to be eco-friendly controlled by spraying fungicide from mindi leaves which contains active ingredient azadirachtin and margocyn as antimicroorganisms. The research was conducted by using Factorial Completely Randomized Design with 2 factors and 3 replications. Priming factors (A) consisted of A0 (control), A1 (immersion), and A2 (humidification). Fungicide factors (B) consisted of B0 (control), B1 (100 grams of Mindi leaves / 2L water), B2 (150 grams of mindi leaves/2L water), B3 (200 grams of mindi leaves/2L of water), and B4 (250 grams of mindi leaves/2L water). Fungicide was given every 7 days after inoculation with 7 times of applications. The results of the research proved that the treatment A2B3 (priming with humidification and fungicides 200 grams of mindi leaves/2L of water) was an effective treatment in reducing the intensity of gall rust disease on sengon with 8,36% of intensity.

Pathogenesis of gall-rust disease on Falcataria moluccana in areas affected by Mount Merapi eruption in Indonesia

Abstract. Rahayu S, Widiyatno, Adriyanti DT. 2020. Pathogenesis of gall-rust disease on Falcataria moluccana in areas affected by Mount Merapi eruption in Indonesia. Biodiversitas 21: 1310-1315. The gall rust pathogen Uromycladium falcatarium affects the fast-growing tree species Falcataria moluccana (Sengon) from seedling to mature stage producing galls on all its parts. Severe infestation causes tree mortality. There were two eruptions of the volcano at Mount Merapi, Java, Indonesia during October-November 2010 near to which Sengon is grown under community forests. This study, conducted in 2014, examined the implications of the volcanic eruptions on the incidence and severity of gall rust disease on Sengon trees growing in areas affected by the eruption. It revealed that the percentage infestation on seedlings caused by teliospores of U. falcatarium collected from areas close to Mount Merapi (3-7 km away-risky area) was significantly higher compared to those collected from trees 7.1-11 (are under alert) and 11.1-15 km (area under threat) away. The teilospores and galls collected from the ‘risky area’ also exhibited morphological variations. The gall rust incidence on different parts of the tree was significantly higher in the ‘risky’ area compared to trees growing in other areas. The incidence of the disease was close to 100% in the risky area but less than 80% in areas ‘under alert and under threat’. Overall, the data indicated that the incidence and severity of gall rust disease was significantly higher in areas close to the Mount Merapi apparently due to increased virulence of the pathogen and increased susceptibility of the trees due to damges caused by the eruption. Conducive environmental conditions such as high relative humidity and temperature in the area may also have favoured this situation. Artifical inoculations using teliospores collected from infected trees in the risky area, area under alert and under threat caused severe infection on seedlings.

Gall rust disease incidence of Falcata (Paraserianthes falcataria (L.) Nielsen) in Falcata – based agroforestry systems in Misamis Oriental, Philippines

Falcata – based agroforestry systems in eastern part of Misamis Oriental is affected by gall rust disease caused by Uromycladium tepperianum (Sacc,) considered as one of the most destructive disease. The objectives of this study at Misamis Oriental, Northern Mindanao were to (i) determine the status of gall rust disease incidence in selected eastern municipalities and city of Northern Mindanao, and (ii) determine the factors and its relationship with gall rust disease. The sampling intensity was 10% or 1,000 m2 of one hectare at each site. Twenty temporary sample plots per municipalities and city were identified and assessed with a total of 140 plots. Each plot contained 15-70 trees for observation. Gall rust disease incidence per municipalities and city varies ranging from occasional to very common. Across site the incidence is considered common (25->50%). Elevation, spacing and age were associated with reduction or increase in gall rust disease incidence in these parts of Northern Mindanao.

KETAHANAN BIBIT SENGON ( Falcataria moluccana (Miq) Barneby & J.W. Grimes) TERHADAP CENDAWAN Uromycladium falcatarium BERDASARKAN ASAL BENIH DAN JENIS PENGENDALI

Gall rust disease caused by Uromycladium falcatarium fungus is one of sengon ( Falcataria moluccana ) diseases in the nursery and field. The purpose of this study was determining the effect of seed sources and controller type against the resistance of sengon seedlings from infection of Uromycladium falcatarium in the nursery. The research design used a factorial completely randomized design with two 2 factors i.e sources of the seed (A1 = seed from the endemic area of gall rust/Kediri; A2 = seed from non-endemic of gall rust/Cianjur) and the type of cotrollers (B1 = no treatment l; B2 = biological fertilizer of Plant Growth Promoting Rhizobacteria (PGPR) (5 g.l -1 ); B3 = Biofungicide (5 g.l -1 ); B4 = biofungicide of soursop leaf extract (10 g.l -1 ); B5 =mancozeb (2 g.l -1 ). Each treatment combination consisted of 10 seedlings repeated 4 times. The observation variables were the disease incidence and intensity, the number of teliospores and thickness of the epidermal cell wall. The results of the study showed that the interaction of seed sources and type of controller affected the number of teliospores and thickness of the epidermis. The lowest number of teliospores (6.48 teliospores) was found in seedlings f rom non endemic gall rust areas with the controller of soursop leaf extract. The thickest epidermal cells (5.43 μ - 5.84 μ) were produced from seedlings from gall rust-free area with PGPR solution controller, soursop leaf extract and mancozeb. The disease intensity in seedlings originating from gall-free areas (3.5 percent) is lower than endemic areas (5.2 percent). PGPR and mancozeb were effective to the infection of fungus because the disease incidence and intensity were low after the 3rd control stage.

Fingerprinting sengon (Falcatria moluccana) accessions resistant to boktor pest and gall rust disease using microsatellite markers

Abstract. Siregar UJ, Rahmawati D, Damayanti A. 2019. Fingerprinting sengon (Falcatria moluccana) accessions resistant to boktor pest and gall rust disease using microsatellite markers. Biodiversitas 20: 2698-2706. Sengon (Falcataria moluccana Miq.) is a multipurpose fast-growing tree species and widely planted as community forest in Indonesia. According to Indonesian Light Wood Association (ILWA) F. moluccana wood products coming from forest industries in Jawa worth US$ 244.46 million export to China alone. The wood dust also has high potential as source for biomass-based energy in the form of wood-pellet. Monoculture plantation however often suffers from stem borer pest, known as boktor (Xystrocera festiva) and a gall rust disease, caused by fungi Uromycladium falcatarium. This research was aimed to characterize accessions of resistant and susceptible sengon individuals to both gall rust disease as well as stem borer pest using microsatellite markers. Totally 50 accessions of resistant and of resistant to stem borer pest were collected from Sumedang, West Jawa Province, while 88 accessions of resistant and of resistant to gall rust disease were sampled from Kediri, East Jawa Province and Sukabumi, Indonesia. Eight microsatellite markers could amplify most of the accessions used in this study and produce polymorphic fragments. High genetic diversity was detected in all of F. moluccana populations, with He ranged from 0.431 to 0.650. AMOVA showed that most genetic variations come from within populations. A dendrogram based on Nei’s genetic distance (1972) clustered some resistant accessions to either stem borer pest or gall rust disease separately from susceptible ones.

Sengon (Falcataria moluccana) prevention from gall rust through seed irradiation: field test in endemic location

The gall rust disease is the diseases of sengon plant (Falcataria moluccana), that it caused by Uromycladium spp. which can cause the decreased productivity. However, at this time not yet retrieved the right techniques to reduce attacks of gall rust disease on sengon plant. Efforts to control gall rust disease at the level of seeds can be through by seed irradiation technique. Irradiation techniques on seeds can be used to increase productivity through increased vigour and seed quality. The aim of the study was to determine the effectiveness of gamma rays irradiation techniques on sengon seeds its shown by the growth and percentage of damage caused gall rust at sengon plantation at Pandantoyo Sub Forest District (RPH), Pare Forest District (BKPH), Kediri Forest Management Unit (KPH), East Java. The research design used a randomized block design consisting of 3 blocks. Each block consists of 10 treatments based on irradiated doses (0, 5, 10, 15, 30, 45, 60, 75, 90 and 105 Gy) and each treatment consist of 20 plants. The parameters observed were percentage of attacked plants that divided into four level of damage: healthy (0%); low (≤ 10%), moderate (≥ 11%-45%) and severe (≥ 46%) and growth of diameter and height. Generally, the health conditions of sengon plantation were affected by gall rust. At 18-months-old, the gamma rays irradiation at 75 Gy was the largest percentage of healthy plants (42.5%) and better than control (24 %). At 25-months-old, the plants derived from seeds that were not irradiated (control) was the largest percentage of plants with severe damage. Gamma rays irradiation does not affect the growth of diameter and height. The highest percentage of healthy plants were at 1st block but the fastest growth of plant diameter was 2nd block.

Morphological and phytochemical characterization of susceptible and resistant sengon (Falcataria moluccana) tree to gall rust disease

Abstract. Rahmawati D, Khumaida N, Siregar UJ. 2019. Morphological and phytochemical characterization of susceptible and resistant sengon (Falcataria moluccana) tree to gall rust disease. Biodiversitas 20: 907-913. Gall rust disease has severely attacked sengon tree (Falcataria moluccana Miq. Barneby & J.W. Grimes)) and it rapidly spread in tree plantations causing the decrease of wood productivity. Although sengon is widely cultivated in several areas in Indonesia, there are limited studies on secondary metabolite composition of its wood. This research was aimed to study differences on morphology, wood anatomy and secondary metabolites content of resistant and susceptible sengon tree trunk to gall rust disease. Both resistant and susceptible tree samples to gall rust were selected from the same plantation plots to minimize environmental effects. Structure of wood samples was observed using Scanning Electron Microscope (SEM) JSM-5310LV. Seven types of secondary metabolites, i.e., alkaloids, flavonoids, saponins, phenolic hydroquinones, tannins, triterpenoids, and steroids were qualitatively analyzed from powdered wood samples. Based on field observations, the gall rust fungi changed the color, texture, pores of the tree surface and decreased wood density. In microscopic observations, sengon trunk, which is resistant to gall rust disease, showed organized and regularly structured wood anatomy and did not show hyphae of the infecting fungi inside the wood. The fungi damaged susceptible sengon trunk as indicated by the dispersed and irregular structure of wood tissue, while the presence of fungal hyphae among wood cells was detected. Phytochemical analyses indicated that trunk of sengon containing flavonoids, saponins, phenolic hydroquinones, tannins, triterpenoids, and steroids, except alkaloids. Sengon trunk, which is resistant to gall rust disease, had stronger reactions of flavonoids, saponins, triterpenoids, and steroids compared to that susceptible one.

Microscopic callus selection of sengon tree (Falcataria moluccana) putative tolerant to Uromycladium falcatarium

The increase of the cultivation area of the sengon tree (Falcataria moluccana) through monoculture cropping system especially in Java has caused an increase in gall rust disease. Infestation of the disease may lead to 100% death of sengon seedlings. Uromycladium falcatarium has been identified as the fungus causing the gall rust epidemic. This research aimed to select calli putative tolerant to gall rust disease. Seeds of ten individual colonies of 3 clones of sengon trees from Purwobinangun district that have been attacked severely by gall rust were used as explant sources. Gall rust filtrate was used as bioagent selection in vitro and the viable calli were selected under a microscope. The callus viability was determined based on the average living cell percentage stained with fluorescence diacetic acids. These viable cells of callus were found to have a good correlation with the tolerance index value. The results showed that callus colony from clone 3 individual 4, clone 5 individual 5, and clone 6 individual 5 exhibited the highest tolerance index value. The cell with different index values to the biotic pathogen filtrate indicated the presence of an enzymatic defence process of the cells against gall rust attack.