Direct Seeded Rice and its Prospects in Nepal: A Review

Direct Seeded Rice (DSR) is an alternative cultivation technique to the conventional Transplanted Rice (TPR). In this method, seeds are directly sown to the field without the necessity of nursery raising and transplanting. DSR can generally be divided into dry-DSR (sowing dry seeds in dry soil), wet-DSR (sowing pre-germinated seeds in moist soil) and water-seeding (sowing dry or pre-germinated seeds in standing water). This helps in saving water alongside the labour and results in early harvest due to quick crop establishment. DSR is proved to be sustainable and eco-friendly since it emits less methane than in TPR. However, there are few constraints associated with DSR such as weed infestation, crop lodging and nutrient loss. If these major issues are fixed, DSR can result in greater economic returns as compared to TPR. In absence of puddling, the soil structure can be maintained which leads to greater yields of succeeding crops. This technique has been successfully practiced in many countries like Srilanka, Malaysia and USA. In developing nations like Nepal, irrigation and labour constraints can be tackled by adopting direct-seeding for rice cultivation.

OPTIMIZATION OF IN VITRO SELECTIVE MEDIA FOR SELECTING ANTHRACNOSIS-RESISTANT FLAX CELLS

Цель исследований – оптимизация селективных сред для проведения отбора in vitro каллусных клеток льна, устойчивых к культуральному фильтрату штаммов возбудителя антракноза и создание in vitro новых генотипов, устойчивых к болезни. В результате исследований уточнен состав культурального фильтрата штаммов антракноза. Выявлено, что токсичность культуральных фильтратов не зависела от вирулентности используемых штаммов – более токсичными оказались культуральные фильтраты штаммов 784 (сильновирулентного) и 780 (средневирулентного) (загнивание и отмирание первичных корешков на 5 сутки наблюдали у 67 – 88% проросших семян), менее токсичны – штаммы 793 (сильновирулентный) и 788 (слабовирулентный) (на 5 сутки загнивание и отмирание первичных корешков отмечено у 9 – 15% проросших семян). Установлено, что морфогенные очаги формировались активнее у генотипов, морфогенный каллус которых переносили на среду с аналогичной или более высокой концентрацией культурального фильтрата. Показано, что на 14 сутки во втором пассаже с большей частотой формировались морфогенные каллусы, почки и побеги при использовании в первом и втором пассажах селективной среды, содержащей культуральный фильтрат в концентрации 40 мл/л, или в первом пассаже – 40 мл/л, а во втором – 44 мл/л. Выделены генотипы, сохраняющие устойчивость к антракнозу в течение трёх поколений на уровне 50 – 60%: НО-78 х Ленок, HJI-103-2 х Ленок, НЛ-40-1 х Ленок, HЭ-38 х Росинка, НЭ-36 х Ленок, НЭ-17 х Ленок, HЭ-16-2 х Росинка. Research objective – optimization of selective media for in vitro selection of flax callus cells resistant to culture filtrate of anthracnose pathogen strains and in vitro creation of new disease-resistant genotypes. As a result of the research, the composition of the culture filtrate of anthracnose strains was clarified. It was revealed that the toxicity of cultural filtrates did not depend on the virulence of the strains used - cultural filtrates of strains 784 (highly virulent) and 780 (medium virulent) turned out to be more toxic (decay and death of primary roots on day 5 was observed in 67 - 88% of germinated seeds), less toxic - strains 793 (strongly virulent) and 788 (weakly virulent) (on the 5th day, decay and death of primary roots was noted in 9-15% of germinated seeds). It was found that morphogenic foci were formed more actively in genotypes, the morphogenic callus of which was transferred to a medium with a similar or higher concentration of the culture filtrate. It was shown that on the 14th day in the second passage, morphogenic callus, buds and shoots were formed with a greater frequency when using in the first and second passages a selective medium containing a culture filtrate at a concentration of 40 ml/l, or in the first passage - 40 ml/l, and in the second - 44 ml/l. Genotypes were identified that retain resistance to anthracnose for three generations at a level of 50 - 60%: NO-78 x Lenok, HJI-103-2 x Lenok, NL-40-1 x Lenok, NE-38 x Rosinka, NE-36 x Lenok, NE-17 x Lenok, NE-16-2 x Rosinka.

High dilutions of Magonia pubescens hidrogel affect germination variables in Sorghum bicolor L. Moench

Introduction: In science homeopathic diseases or physiological disorders are not considered just a result of abiotic and biotic factors, but rather a consequence of loss of organic system homeostasis. Homeopathic science is currently being used efficiently in the control of plagues[1], plant diseases[2], in the increase of medicinal plants’ active principles[3] and in plant metabolism[4,5]. Although actual results, both in the academic and field-level, very little is known about physiological mechanisms action of homeopathic medicine on germination process[6]. This work aims to study the effect of M. pubescens hydrogel, on some physiological variables of sorghum germination (Sorghum bicolor L. Moench). Material and methods: The experiment was conducted at Homeopathy and Plant Physiology of Biology Department at UEM in the period from 04/05/06 to 30/12/06. M. pubescens (tingui) seeds were obtained from the region of Montes Claros - Minas Gerais. The M. pubescens hidrogel was obtained from the external centrals wrappers of 4 dry seeds, after they have been disposed in petri dishes with distilled water for a period of 36 hours of soaking (25oC). The hydrogel mother tincture was prepared according to Manual of Technical Standards for Homeopathic Drugstore[7] 3rd ed (2003), in the proportion of a hidrogel part (5g) to ten parts (50g) of absolute alcohol 70% and stored in a glass amber (capped and protected from light). After 15 days of maceration, the solution was filtered and after 48h at rest, the mother tincture was considered ready for use. The dilution 1cH (Centesimal Hahnemannian) was obtained by adding 0.2 ml of the mother tincture in 19.8 ml of distilled water (1/100) and sucussioned 100 times (33 sucussions s-1) by mechanical arm dynamizer with automatic stop (Model Denise 50 - AUTIC). The subsequent dilutions (2cH to 30cH) were obtained from the same procedure, starting from the dilution 1cH. Bioassay: In petri dish containing 15 seeds of sorghum in a circular distributed were added 10 ml with their dilutions (3, 6, 9, 12, 15, 20 and 30cH) and the control containing distilled water. The petri dishes were placed in a growth chamber (type BOD), temperature of (25 ± 2)°C and photoperiod of 16h. The variables were analyzed by germination period of 73.5h as described below: · Germination (%G): %G = (∑ni.N-1)x100 , where ∑ni, is the total number of germinated seeds in relation to the number of seeds put to germinate, expressed in percentage; · Germination average time (GAT): GAT = ∑ni . ti / ∑ni , where ni is the number of germinated seeds within a certain interval of time ti-1 and ti; expressed in hours. · Germination average speed (GAS), expressed in hours): GAS = ∑ni / ∑ni . ti · Germination speed index (GSI): IVG = G1 / N1 + G2 / N2 + ........ Gn / Nn , where G1, G2....Gn is the number of germinated seeds and N1, N2, ... Nn is the number of hours after sowing. The total number of germinated seeds, at each time (12h) was also analyzed. Seeds were considered germinated when the radicle had 1 to 2 mm of lengths. Experimental design: The experimental design was randomized block with 4 replications, totaling 32 experimental units. It was adopted the double-blind methodology, to avoid possible interference or direction by the researcher. Statistical Analysis: The data were analyzed by ANOVA and the averages compared by Scott-Knott test (p≤0.05). The twinning combined data were analyzed for interaction germination x time (G x T) by F test to 5% of probability. Results and discussion: The homeopathy of Magonia pubescens hydrogel affected on the germination kinetic variables of sorghum seeds, when compared with the control (Fig. 1). This effect was most observed in the initial process of germination (from 13h). Research accomplished by Salgado-Labouriau (1973) [8] showed that the hydrogel formed from the external wrapper Magonia pubescens seeds, does not contain inhibiting, but contains factors that accelerate the germination process. Apparently, these results seem contradictory. However, for the homoeopathic optics, some used medicines in a considered way might have determined effect. Already in high diluted doses this behavior can be reversed, as it happens with some drugs. This behavior in pharmacokinetics is denomined Hormesis. When diluted and given dynamism, the product of hydrogel, instead of stimulating, it can delay the germination for the same phenomenon. Hormesis is not yet explained by science. Homeopathy of the Magonia pubescens gel significantly increased the germination average time (GAT) of sorghum seeds and reduced the germination average speed (GAS) and the germination speed index (GSI) (Fig. 2A, B and C). The values of these variables suggest that homeopathy, somehow slowed the speed of sorghum seeds soaking. Conclusion: The results here presented suggest that high dilutions of Magonia pubescens hidrogel can be used in future experiment such as bioherbicide.

Poisson distribution and process as a well-fitting pattern for counting variables in biologic models

One of the major criticisms directed to basic research on high dilution effects is the lack of a steady statistical approach; therefore, it seems crucial to fix some milestones in statistical analysis of this kind of experimentation. Since plant research in homeopathy has been recently developed and one of the mostly used models is based on in vitro seed germination, here we propose a statistical approach focused on the Poisson distribution, that satisfactorily fits the number of non-germinated seeds. Poisson distribution is a discrete-valued model often used in statistics when representing the number X of specific events (telephone calls, industrial machine failures, genetic mutations etc.) that occur in a fixed period of time, supposing that instant probability of occurrence of such events is constant. If we denote with λ the average number of events that occur within the fixed period, the probability of observing exactly k events is: P(k) = e-λ λk /k! , k = 0, 1,2,… This distribution is commonly used when dealing with rare effects, in the sense that it has to be almost impossible to have two events at the same time. Poisson distribution is the basic model of the socalled Poisson process, which is a counting process N(t), where t is a time parameter, having these properties: - The process starts with zero: N(0) = 0; - The increments are independent; - The number of events that occur in a period of time d(t) follows a Poisson distribution with parameter proportional to d(t); - The waiting time, i.e. the time between an event and another one, follows and exponential distribution. In a series of experiments performed by our research group ([1], [2]., [3], [4]) we tried to apply this distribution to the number X of non-germinated seeds out of a fixed number N* of seeds in a Petri dish (usually N* = 33 or N* = 36). The goodness-of-fit was checked by different tests (Kolmogorov distance and chi-squared), as well as with the Poissonness plot proposed by Hoaglin [5]. The goodness-of-fit of Poisson distribution allows to use specific tests, like the global Poisson test (based on a chi-squared statistics) and the comparison of two Poisson parameters, based on the statistic z = X1–X2 / (X1+X2)1/2 which is, for large samples (at least 20 observations) approximately standard normally distributed. A very clear review of these tests based on Poisson distribution is given in [6]. This good fit of Poisson distribution suggests that the whole process of germination of wheat seeds may be considered as a non-homogeneous Poisson process, where the germination rate is not constant but changes over time. Keywords: Poisson process, counting variable, goodness-of-fit, wheat germination References [1] L.Betti, M.Brizzi, D.Nani, M.Peruzzi. A pilot statistical study with homeopathic potencies of Arsenicum Album in wheat germination as a simple model. British Homeopathic Journal; 83: 195-201. [2] M.Brizzi, L.Betti (1999), Using statistics for evaluating the effectiveness of homeopathy. Analysis of a large collection of data from simple plant models. III Congresso Nazionale della SIB (SocietàItaliana di Biometria) di Roma, Abstract Book, 74-76. [3] M.Brizzi, D.Nani, L.Betti, M.Peruzzi. Statistical analysis of the effect of high dilutions of Arsenic in a large dataset from a wheat germination model. British Homeopathic Journal, 2000;, 89, 63-67. [4] M.Brizzi, L.Betti (2010), Statistical tools for alternative research in plant experiments. “Metodološki Zvezki – Advances in Methodology and Statistics”, 7, 59-71. [5] D.C.Hoaglin (1980), A Poissonness plot. “The American Statistician”, 34, 146-149. [6] L.Sachs (1984) Applied statistics. A handbook of techniques. Springer Verlag, 186-189.

Assessment of Phenol Detoxification by Rhodococcus aetherivorans UСM Ac-602 Using the Phytotesting Method

Monoaromatic compounds are related to widespread pollutants of soil and groundwater. Among them phenol is one of the most toxic and carcinogenic compounds. Therefore biodestruction of phenol is of much importance for environment protection. The use of metabolic potential of microorganisms for depolluting environment is a safe and economical alternative to widely used physicochemical methods. Aim. To assess efficacy of phenol detoxification with strain Rhodococcus aetherivorans UСM Ac-602 using the phytotesting method. Methods. Bacteria were cultivated in liquid mineral medium with initial concentration of phenol 500, 750 and 1000 mg/L as a single source of carbon and energy. Cultivation time was 24 h, 48 h and 72 h respectively. Phytotoxicity was determined in express-test with use of seeds of spring wheat variety “Pecheryanka” (Triticum aestivum L.). Plant seeds were incubated by temperature 20±2°C during 7 days in Petri dishes with filter paper treated with respective phenol aqueous solutions or post-fermentative cultural fluids (PFCFs). PFCFs were obtained after cultivation of strain in growth medium with same concentration of phenol. Morphometric parameters of wheat were assessed against control plants cultivated on distilled water. Comparative analysis of samples toxicity and toxicity class determination was performed according to Kabirov method by calculation of index of test factor toxicity (ITF). Results. Phenol aqueous solutions and PFCFs were much different in effect on wheat. Phenol solutions 500 and 700 mg/L have shown significant inhibitory effect on all initial growth parameters of test plants. The weakest growth inhibition was induced by phenol concentration of 500 mg/L which caused decrease in number of germinated seeds by 59.6%, shoot length – by 59.7%, root length – by 84.5%, sprout dry weight – by 35.0%. In the presence of phenol concentration of 750 mg/L these indicators increased by 7−30%; roots of test plants were the most sensitive to effect of phenol. Phenol concentration of 1000 mg/L caused total seed mortality. Unlike phenol aqueous solutions PFCFs have shown insignificant effect on all morphometric indicators of plants compared to control. Similar effects on plants were observed in the presence of PFCFs obtained from cultivation of strain R. aetherivorans UСM Ac-602 in the growth medium with initial concentrations of phenol of 500 and 750 mg/L. Under the influence of these PFCFs, the number of germinated seeds decreased on average by 15.8%, root length decreased by 19.8%, at the same time shoot length and their dry weight increased by 17.8% and 7.2% respectively. More negative effect on wheat was shown by PFCF obtained after strain cultivation on medium with phenol concentration 1000 mg/L. It caused reduction in number of germinated seeds by 18.0 %, shoot length – by 25.3%, root length – by 29.0%, sprout dry weight – by 7.2%. For phenol aqueous solutions ITFs had much lower values 0–0.40 than for PFCFs (0.71–1.0). Conclusions. Based on data obtained in this research it was concluded that strain R. aetherivorans UCM Ac-602 performs active detoxification of high-concentrated phenol-containing media. Analysis of calculation results for ITF medium values (ITFm) had shown that under the influence of studied strain there was a decrease in toxicity of phenol solutions (500, 750 and 1000 mg/L). According to Kabirov toxicity scale it was assessed that toxicity of phenol solutions with initial values of classes II (high) and I (very high) was decreased to IV (low) and V (normal level). Our results demonstrate ecological safety of the end products of phenol destruction with strain R. aetherivorans UCM AC-602 and prospects of its use in biotechnologies for environment detoxification from phenol pollutions.

Biotic and Abiotic Interactions Shape Seed Germination of a Fire-Prone Species

Both biotic and abiotic environmental filters drive the occurrence, distribution, and persistence of plant species. Amongst drivers that influence the distribution of plants in harsh environments, seed predation and temperature are particularly important in habitats that are prone to fire. In this study, we highlight the combined effects of predation and high temperature simulating fire to understand its effects on the germination percentage and germination speed of the fire prone species Copaifera oblongifolia. Groups of seeds attacked by the beetles Rhinochenus brevicollis and Apion sp., seeds manipulated by the ant Atta laevigata, and seeds left intact were put to germinate in controlled environments. To evaluate the effects of abiotic filters, seeds with intact elaiosomes and seeds with elaiosomes removed by the ant Atta laevigata were exposed to temperatures of 27, 60, 100, and 200 °C. The results showed that only 2.8% of the seeds attacked by R. brevicollis germinated. Seeds attacked by Apion sp. germinated faster, followed by seeds with their elaiosomes removed and seeds with intact elaiosomes. Seeds attacked by Apion sp. had the lowest germination percentage. The temperature of 200 °C killed seed embryos, whereas seeds exposed to 100 °C took longer to germinate than seeds exposed to other temperatures. Our results reveal that fire intensity and seed damage are important drivers of seed germination of C. oblongifolia.

Germination of palm seeds under periods of rehydration

Palm seeds are indicative of being recalcitrant species. Seeds germination for many species, is slow and uneven, even in favorable conditions, often due to the resistance of the woody endocarp that makes them impermeable to water. Most species also have the characteristic of not tolerating the drying process at low moisture levels, thus losing their viability. In view of these considerations, the objective was to evaluate the effect of different periods of rehydration on the germinative process of seeds of royal palm, dwarf palm and jeriva. Seeds were homogenized and immersed in water containing 3 times their volume, with daily replacement. The experimental design used was completely randomized, with 5 treatments (0, 3, 6, 9, and 12 days of rehydration), with 4 replications of 25 seeds. The seeds were placed in transparent “gerbox” plastic boxes containing medium vermiculite as substrate and placed in BOD with a photoperiod of 16-hour of light and their respective optimum temperatures for each species. The number of germinated seeds was counted every 2 days until germination stabilized. The variables analyzed were germination percentage, germination speed index (GSI), average germination time (AGT) and distribution of germination over the days. Rehydration for 3 days increased the germination rate of royal palm seeds. For dwarf and jeriva species, rehydration did not influence the analyzed variables. The GSI and AGT were negatively influenced by the rehydration periods for royal palm. Rehydration prolonged the peak of germination of the studied species.

Germination, Growth and Yield Responses of Leaf Amaranth (Amaranthus hybridus) to Rates and Times of Poultry Manure Application

Manures are more environment-friendly and effective in improving soil fertility, hence their recent preference over inorganic fertilizers. Poultry manure is believed to be the most valuable manure produced by livestock. However, the application had always been only before sowing, unlike the inorganic fertilizers that are, generally, applied after sowing/planting of crops. Therefore, the effects of broiler droppings applied at different rates and times were evaluated on seed germination, growth and yield of leaf amaranths, during the raining season of year 2019. Broilers droppings were applied at 0, 30 and 50 tha-1, at 1 and 2 week (-s) before sowing, at sowing and 1 and 2 (week)s after sowing of amaranth seeds. The experiment was factorial and treatments were replicated thrice in a randomized complete block design. Growth parameters measured were: Plant height, number of leaves, stem girth, leaf area, number of germinated seeds , and yield were measured at 7, 8 and 9 weeks after sowing (WAS). The data generated were subjected to ANOVA at α0.05. At 7 WAS, application of 50 tha-1 manure at sowing produced the highest plant height (17 cm), stem girth (7.40 cm), number of harvested stands (18.33) and marketable yield (7.95 tha-1) with significant differences. At 8 WAS, the highest yield (5.83 tha-1 was obtained from plots treated with 30 tha-1 of poultry dung applied at 2 weeks before sowing while more seeds (27) germinated on both plots treated with 50 t/ha of broiler droppings applied at sowing and 1 WAS. The best recorded values for number of germinated seeds (27) and yield (2.83 tha-1) at 9 WAS were obtained from 50 tha-1 of broiler droppings applied at sowing. 50 t/ha of broiler droppings, at sowing compared well with poultry droppings applied at any rate before sowing.

STUDY OF THE INFLUENCE OF NATIVE AND GERMINATED PUMPKIN AND WATERMELON SEEDS ON THE QUALITY OF DOUGH AND BREAD

The paper examines the effect of native and germinated pumpkin and watermelon seeds on the quality of semi-finished and finished bread products. Native and germinated seeds, pre-dried and ground into flour, were used as an additive to bread in the amount 5%, 10%, 15% by weight of the flour. Pumpkin and watermelon seeds were added in order to enrich the bread with micronutrients. The influence of these additives on the quantity and quality of gluten has been analysed. It has been found that the addition of pumpkin seed flour in quantities of 5%, 10% and 15% by weight of wheat flour leads to a decrease in the gluten content and an increase in its elasticity. The study has shown that adding native pumpkin seeds does not have a significant effect on the moisture and acidity of semi-finished and finished products, and adding germinated seeds leads to a slight increase in these parameters. Thus, the moisture content of the crumb with native pumpkin and watermelon seeds added increased by 0.2–1.3%, as compared with the reference sample, and with germinated seed flour added, it increased by 0.5–2.2%. The acidity of the crumb changes slightly, within experimental error. According to the physicochemical quality parameters, the most practical amount of the additives is 5% by weight of wheat flour. A comparative analysis has been carried out to establish how addition of 5% of native and germinated pumpkin and watermelon seeds changes the organoleptic properties of bread. The analysis has shown that ready-made bread products containing native pumpkin seeds taste better and have better olfactory properties than products with germinated seeds. The nutritional and calorific values of the reference sample and of bread with 5% of pumpkin and watermelon seed flour have been compared and characterised. It has been found that the addition of native pumpkin seeds will increase the content of minerals: of iron by 230%, of magnesium by 116%, and of potassium by 118%. The addition of native watermelon seeds will increase the phosphorus content by 13%. As a result of this research, the prospects of using flour of native pumpkin and watermelon seeds to fortify wheat bread have been shown

Diversity of resident plant communities could weaken their allelopathic resistance against alien and native invaders

Elton’s classic diversity-invasibility hypothesis posits that diversity of resident communities increases resistance against invaders. We tested whether the diversity-invasibility relationsip might be mediated by allelopathic effects of the resident species. In a large germination experiment, we exposed seeds of six alien and six native test species to leachates of one, three, six or twelve species. The leachates tended to slightly delay germination, and almost all single-species leachates reduced the proportion of germinated seeds. Nevertheless, the overall effect of the plant leachate mixtures on the proportion of germinated seeds was not significant. This was because a higher diversity of the leachates increased the proportion of germinated seeds, particularly for native test species. Among the six alien test species, it was only the most invasive one that benefited from increased diversity of the leachates, just like the natives did. Overall, our findings suggest that allelopathy of diverse communities does not provide resistance but could actually facilitate the germination of invaders.