ESTIMATING VARIABILITY, HERITABILITY, AND GENETIC ADVANCE OF RICE GENOTYPES IN MID-HILLS OF NEPAL

<p>Rice is an essential staple food in Nepal but researches and varietal improvement programs are rarely carried out due to inadequate variability study. The field study was carried to diagnose the influence of genetic and environmental factors on yield traits to aid future rice breeding programs. Twelve genotypes were arranged in randomized complete block design with three replications from July to November 2019 at the research field of the Institute of Agriculture and Animal Science, Tribhuvan University, in the hilly area of Nepal. Analysis of variance showed significant difference for days to 50% booting, days to 50% flowering, plant height, panicle length, flag leaf area, filled grains per panicle, unfilled grains per panicle, fertility percentage, effective tillers m^-2, straw yield, grain yield, 1000-grain weight, and harvesting index indicating the presence of variation in genotypes. LPN BR-1615 was the most promising genotype in grain yield. The values of Phenotypic Coefficient of Variation (PCV) were higher than Genotypic Coefficient of Variation (GCV) for each trait and low difference between them was found for days to 50% booting, days to 50% flowering, plant height, panicle length, grain yield, thousand-grain weight, fertility percentage, and harvesting index. Plant height, effective tillers m^-2, and grain yield showed high heritability (i.e. 93.2%, 60.5% and 92.6%, respectively) and higher genetic advance as percentage of mean (i.e. 46.5, 34.6 and 50.1, respectively) . Thus, the experiment revealed that selections favoring plant height, effective tillers m^-2, and grain yield would help in effective breeding programs of rice in future.</p>

SSR MARKERS REVEALED GENETIC DIVERGENCE OF RICE BROWN PLANTHOPPER POPULATIONS MAINTAINED ON TWO SETS OF DIFFERENTIAL HOST VARIETIES

<p>Resistance screening of promising rice lines in Indonesia requires the use of brown planthopper (BPH) biotypes 1, 2, and 3. Three BPH populations have been raised as biotypes 1, 2, and 3 on differential rice host of improved varieties Pelita I-1 (no <em>Bph </em>gene), IR26 (<em>Bph1</em>), and IR42 (<em>bph2</em>), respectively. Three alternative populations have also been developed on the respective traditional varieties TN1 (no <em>Bph </em>gene), Mudgo (<em>Bph1</em>), and ASD7 (<em>bph2</em>). Although these populations displayed two virulent patterns other than biotype 1 to 3 phenotypes, they were expected to be discriminated into two virulence groups by SSR analysis. The study aimed to investigate the level of genetic variation among the six BPH populations using SSR markers and to relate it with the observed virulence patterns. Genotyping of 30 females with 29 polymorphic SSR markers revealed higher genetic parameter values in populations reared on improved varieties than those on traditional varieties. This difference was marked as two population clusters in PCoA plots corresponding to the host variety type, in contrast to the previous assumption that clustering would be based on virulence patterns. The presence of individuals with unwanted virulence allele, either resulting from contamination during the long period of rearing or lack of host adaptation period, is suspected. The result of this study indicates that the six populations are not suitable for resistance screening. Virulence selection must be performed until they attain biotype 1 to 3 phenotypes which can be genetically separated by DNA markers.</p>

EFFECT OF AMELIORANT ON GROWTH AND YIELD OF RICE AT TIDAL PADDY FIELD

<p>Rice (<em>Oryza sativa </em>L.) is the most important and strategic food crop in Indonesia, but low productivity in tidal paddy fields is a serious problem that must be overcome. The application of ameliorant would be worthy to increase the growth and yield of rice in tidal paddy fields. The study aimed to investigate the effect of ameliorant application on growth and yield of rice varieties in tidal paddy fields. The study was arranged in a split plot design with five replications. Rice varieties tested were Inpari 34, Dendang, Inpara 9, Inpari 35, and Ciherang as the main plot, and ameliorant types studied were humic acid, gypsum, zeolite, and organic fertilizer as the subplot. The results showed that the use of different rice varieties and amelioran types significantly increased the growth and yield of rice. Inpara 9 produced 7.6 t.ha-1 dry milled grain (DMG) or increased by 33.3% compared to Ciherang variety. Humic acid application at 25 kg ha-1 increased grain yield by 21.3% higher than that without ameliorant treatment. The best treatment to increase the growth and yield of rice in tidal paddy field was a combination of humic acid 25 kg.ha-1 and Inpari 34 which produced the DMG of 8.6 t ha-1 or 41% higher compared to Ciherang without ameliorant.</p>

GENETIC ANALYSIS OF QUALITATIVE AND QUANTITATIVE TRAITS AMONG PROGENIES OF ENSET CLONES ORIGINATED FROM SOUTHERN ETHIOPIA

<p>The present cultivated enset (<em>Ensete ventricosum</em>) clonal landraces in Ethiopia originated from few wild progenitors. However, enset has a mixed mode of reproduction in which, the wild enset reproduces sexually through seeds, while cultivated enset is generally propagated vegetatively. The objectives of this study were to determine the genetic structure of enset cultivars through genetic analysis of qualitative morphological traits and estimate their genetic variability by evaluating the quantitative agronomic traits data generated from progenies of cultivated and wild enset genotypes. Hence, seeds collected from six cultivated and four wild enset genotypes were used for this study. Data on four qualitative and six quantitative morphological traits were recorded from the progenies of the 10 enset genotypes. Progenies of seven enset genotypes segregated in a 3:1 segregation ratio while progenies of the remaining genotypes segregated differently for the qualitative traits considered. With regard to the quantitative traits, the progenies of the 10 enset genotypes differed significantly for five of the six traits except pseudostem length. The cultivated clones, in general performed better than that of the wild types. Moderate heritability (h2b) estimates and high genetic advances were obtained for leaf length (0.38, 62.0%), pseudostem circumference (0.35, 78.5%), and plant height (0.30, 19.1%) indicating selection for these traits indirectly improves economic yield of enset clones. This study demonstrated the possibility of creating genetic variation through selfing the existing enset genotypes for traits of interest and making improvements either through selection or crossing the elite types to develop novel enset cultivars.</p>

POTENTIAL OF ENDOPHYTIC FUNGI DERIVING FROM ASIATIC PENNYWORTH TO PRODUCE ANTIOXIDANTS

<p>Asiatic pennyworth is a medicinal plant that contains triterpenoids, saponin, flavonoids, and tannins which possess antioxidants. Endophytic fungi from the plant could produce a similar compound; therefore, antioxidants could be made in the laboratory if the fungi are isolated. This study aimed to evaluate the potential of endophytic fungi isolated from Asiatic pennyworth to produce antioxidants. The study used 34 endophytic fungal isolates from Asiatic pennyworth accessions of Malaysia (17 isolates) and Bengkulu, Indonesia (17 isolates) collected by the Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development. The fungi were propagated in a potato dextrose broth medium, then mycelia mats and filtrates were separated and then freeze-dried. The antioxidant activities were first tested with 1,1-diphenyl-2- picrylhydrazyl (DPPH) using thin layer chromatography (TLC), then UV-Vis spectrophotometry λ517 nm with five variations of concentration. Results showed all 34 fungal isolates have antioxidant activities based on a yellowish-white color change after applying 0.002% DPPH solution of the TLC method and IC50 value of the UV-Vis spectrophotometer. The highest antioxidant activity was shown by <em>Aspergillus austroafricanus </em>MB 1 (IC50 = 12.08 ppm) from Bengkulu accession and <em>A. oryzae </em>MM 13 (IC50 = 10.29 ppm) from Malaysia accession. <em>A. austroafricanus </em>MB 1 produced more antioxidant compounds (seven) than <em>A. oryzae </em>MM 13 (six). The antioxidant compounds produced by both endophytic fungi included in the group of flavonoids, fatty acids, and carboxylic acids. The research implies that <em>A. austroafricanus </em>MB 1 and <em>A. oryzae </em>MM 13 could be further developed as sources of antioxidants.</p>

INTEGRATED BIOLOGICAL TECHNOLOGY TO CONTROL MUNGBEAN PESTS AND DISEASES

The main constraints to increase mungbean production in Indonesia are pests and diseases. The application of integrated biological agents can improve the efficacy of controlling the mungbean pests and diseases. The study aimed to determine the efficacy of integrated biological agents to suppress mungbean pests and diseases. This field research was conducted from May to July 2018 using a randomized block design with seven treatments and four replicates. The treatments were: T1 = Trichol + NSP, T2 = Trichol + SlNPV, T3 = Trichol + NSP + SlNPV, T4 = Trichol + NSP + SlNPV + BeBas, T5 = Trichol + NSP + SlNPV + BeBas + GE, T6 = chemical pesticides, and T7 = control. The results showed that the highest efficacy occurred in T4 and T5 treatments which saved the yield loss from major pests and diseases attack, and did not differ significantly with chemical pesticides (T6). Treatments T4 was able to reduce the development of soil borne diseases by 3% and suppress Spodoptera litura attack by 9.8% as compared to chemical treatment. T4 was also more efficient than T5 because it uses less biological agents. The advantage of biological agents is compatible if they were used together with predators such as Oxyopes sp., Paederus sp. and Coccinella sp; and also Telenomus sp. and Trichogramma sp. parasitoids. On the other hand, the chemical pesticides (T6) killed all existing natural enemies. Therefore, T4 could be recommended for controlling mungbean pests and diseases.

CRITICAL VARIABLES OF MORPHO-PHYSIOLOGICAL RICE PLANT UNDER STAGNANT FLOODING CONDITIONS

<p class="abstrakinggris"><span lang="EN-US">Stagnant flooding (SF) stress has contributed decreasing rice production in Indonesia. The study aimed to explore critical variables of rice growth that contribute to the decreasing grain yield under SF conditions and a common irrigation system (control). The experiment was arranged in a complete randomized block design with four replications to test 10 rice genotypes (Inpari 30 Ciherang Sub-1, Inpara 3, Inpara 4, Inpara 8, IRRI119, IRRI154, IR42, IR14D121, IR14D157, and Tapus). The water depth was managed according to the farmer’s practices for control, while for SF plots the standing water depth was gradually increased from 35 days after transplanting and was maintained at 50 cm until harvest. Results showed that plant height, tillering ability, leaf greenness, panicle number per hill and grain filling percentage were critical growth variables that affect grain yield at optimal conditions. The yield of the 10 genotypes decreased by 25–50% under SF conditions. Inpara 3 had the stable yield in those two watering conditions. Therefore, it could be used as a check variety for SF condition. Inpara 9 and IRRI119 experienced decreased yield of more than 50% under SF conditions. The key factors determining the decreased yield were tillering ability and green leaf level. Optimization of the two variables at SF conditions will largely determine rice yield associated with panicle number per hill and grain number per panicle. Results of the study are useful as preliminary recommendations for designing new variety and cultivation techniques to reduce the impact of SF stress on rice yield.</span></p>

GIBBERELLIC ACID PRIMING ENHANCES MAIZE SEED GERMINATION UNDER LOW WATER POTENTIAL

<p class="abstrakinggris"><span lang="EN-US">Germination is a portentous yield determining factor that is a challenge in the low water potential environment due to disrupted imbibition. Hormonal seed priming can markedly increase the germination on maize even in such a stressful environment. Therefore, research was aimed to analyze the application of gibberellic acid (GA₃) priming to maize seeds to minimize the deleterious effects of reduced water potential. GA₃ priming was done at 0, 50, 100, 150, and 200 ppm for 12 hours and subjected to drought levels of 0, 0.15, 0.50, 1.05, and 1.75 MPa by using NaCl solution. Different germination parameters, i.e., germination percentage, mean germination time, germination index, relative water content, seedling vigor index, root length, and shoot length, were determined on the final day of the experiment. The results showed that all germination parameters were adversely influenced by low water potential. Every level of GA₃ priming has hastened all parameters. GA₃ priming at 100 ppm decreased the mean germination time by 35 hours under 1.75 MPa compared to non-primed seeds. GA₃ priming increased the shoot length of maize seedlings with a shoot length of 2.9 cm in non-primed seedlings compared to 6.4 cm in 200 ppm GA₃ priming under 1.05 MPa. GA₃ priming is the best method for the early establishment of maize seedlings in low water potential conditions. As a result, it may be utilized as a low-cost and straightforward approach for establishing maize crops under saline and drought conditions.</span></p>

RESISTANT LEVEL OF SOYBEAN GERMPLASM AGAINST POD SUCKING BUGS (Riptortus spp.)

<p class="abstrakinggris">Increasing productivity of soybean has often been constrained by pod sucking bugs (<em>Riptortus</em> spp.) which caused a serious damage and yield losses up to 80%. Breeding for obtaining soybean variety resistant to pod suckers needs the availability of soybean germplasm resistant to the pest. The study aimed to obtain a candidate for soybean variety resistant to Riptortus spp. through the selection of 100 accessions of soybean. The study included the preparation of test plants and test insects, pest infestations, observations, and looking for a practical screening method for pod sucking pests. The experiment used a completely randomized design for two treatments (infested and non-infested <em>Riptortus</em> spp.). Cikuray variety and PI-092734 accession were used as a control. Results showed that there was a very low correlation among variables observed. Twelve soybean accessions showed a resistance to <em>Riptortus </em>spp., i.e. C7301-113AC-POP, Lokal Madiun-3549, Lokal Klungkung, ML.2974, Singgalang, Lokal Jepara, Lokal Jatim, Lokal Trenggalek, Lokal Tulungagung, Lokal Tabanan, Lokal Blitar, and Lokal Kuningan 10. These accessions were more resistant than the popular released variety such as Wilis, Grobogan, Detam 2, and Gepak Ijo. Small seed size was not a major determinant of soybean resistance to pod suckers. The addition of observational components, i.e. probing preference and oviposition, indicated that crop damage was indirectly influenced by the high frequency of probing and oviposition, although its relation to plant tolerant mechanisms still needs further investigation. Indeterminate plant types require further validation as to whether they contribute significantly to plant resistance against pod sucking insects.</p>

EFFECT OF SCREEN HOUSE MODIFICATION AT FLOWER BUD STADIA ON FLOWER QUALITY OF CHRYSANTHEMUM AT MEDIUM UPLAND ELEVATION

<p class="abstrakinggris">Higher temperature and light intensity at the medium upland elevation decrease the number of blooming flowers, flower diameter, and red color flower intensity of <em>Chrysanthemum morifolium</em>compared to that at the high upland elevation. The environmental modification was needed during the flower development phase to improve the quality of chrysantheum at a medium upland elevation. The study aimed to find the suitable screen house environmental modification for increasing the chrysanthemum quality at the medium upland elevation. The study consisted of two factors. First, environmental modification of a screen house, such as (1) control, (2) the addition of shading net on the rooftop of the screen house, (3) the addition of a misting system in the screen house, and (4) the addition of a combination of shading net on the rooftop and misting system in the screen house. Second, the chrysanthemum varieties, including (1) Yastayuki (white flower), (2) Arosuka Pelangi (yellow flower), and (3) Socakawani (red flower). Experiments were arranged in a completely randomized design with three replications. Data were analyzed by combined ANOVA. The results showed that either the addition of a shading net or misting system reduced the number of flower buds growing. The competition among flower buds was found to be reduced by decreasing the number of flower buds. Consequently, the number and diameter of the blooming flower increased. The addition of a shading net on top of the screen house was the most suitable environmental modification to increase the chrysanthemum quality at the medium upland elevation.</p>