Effect of irrigation levels and foliar application of fertilizers on some agronomic and oil characteristics of castor bean (Ricinus communis L.)

To study the effect of irrigation levels and foliar application of fertilizers on some agronomic and oil characteristics of castor bean, an experiment was conducted at the East Azarbaijan Agricultural Research and Education Center, Tabriz, Iran in 2017-2019 cropping seasons. The experiment was laid out as a split-plot design based on a completely randomized block design with three replications. In the present study, main cluster length, number of branches, number of capsules per plant, number of seeds per capsule, 100-grain weight biological yield, grain yield, oil percent and oil yield were measured. Irrigation intervals (normal irrigation (irrigation after 60 mm), irrigation after 80 mm and 140 mm of evaporation) was established as main plots and the foliar applications of fertilizers (N, K, S, N + K, and N + S, K + S, N + K + S and control) input as sub-plots. The results showed that, except for the oil percentage, all the examined traits were decreased by water limitation. The highest values of the traits, other than the 100-grain weight, were obtained for foliar application of N + K + S. This treatment improved the grain yield per unit area under normal irrigation and moderate irrigation and severe stresses by 62.76%, 41.46% and 28.98% respectively. Thus, the foliar application of S (2000 ppm) + N (3000 ppm) + K (3000 ppm) fertilizer is the best treatment for mitigating some harmful effects of water deficit on castor bean.

Post-mortem characterization of Dorper x Santa Inês lambs fed diets containing alternative foods

The objective of this study was to evaluate the post-mortem characteristics of lambs fed diets containing alternative foods. Twenty lambs, castrated Dorper x Santa Inês males, aged approximately 90 days and with mean weight of 20 kg were used. Experimental diets were composed of ground corn, soybean meal, mineral supplement, urea and Tifton-85 hay (forage). In addition to these ingredients, cottonseed, sunflower meal and castor bean cake were used as alternative foods in the proportions of 10, 8 and 8% of %DM, respectively. The experiment lasted 106 days, with 14 days for adaptation and 92 days for evaluation and data collection. At the end of the confinement period, the lambs were slaughtered, and the carcasses kept under cooling for a period of 24 hours. The measurements of pH, carcass temperature (internal and external) were measured in the Longissimus lumborum muscle, as well as the temperature and relative humidity of the cold chamber were measured. Muscle pH was altered as a function of diet and reached a value of 5.78 (lower pH) when lambs received the diet with castor bean cake. The internal carcass temperature was higher in the lambs that received the diet containing cottonseed (19.98°C), sunflower meal (19.71°C) and castor bean cake (19.87°C). The alternative foods can be used as ingredients in the formulation of diets for Dorper x Santa Inês lamb, for promoting the proper development of the post-mortem process, characteristic of good quality sheep meat.

An integrated omics analysis reveals the gene expression profiles of rapeseed, castor bean, and maize for seed oil biosynthesis

Background Seed storage lipids are valuable for human diet and for the sustainable development of mankind. In recent decades, many lipid metabolism genes and pathways have been identified, but the molecular mechanisms that underlie species differences in seed oil biosynthesis are not fully understood. Results To investigate the molecular mechanisms of seed oil accumulation in different species, we performed comparative genome and transcriptome analyses of rapeseed and castor bean, which have high seed oil contents, and maize, which has a low seed oil content. The results uncovered the molecular mechanism of the low and high seed oil content in maize and castor bean, respectively. Transcriptome analyses showed that more than 61% of the lipid- and carbohydrate-related genes were regulated in rapeseed and castor bean, but only 20.1% of the lipid-related genes and 22.5% of the carbohydrate-related genes were regulated in maize. Compared to rapeseed and castor bean, fewer lipid biosynthesis genes but more lipid metabolism genes were regulated in the maize embryo. More importantly, most maize genes encoding lipid-related transcription factors, triacylglycerol (TAG) biosynthetic enzymes, pentose phosphate pathway (PPP) and Calvin Cycle proteins were not regulated during seed oil synthesis, despite the presence of many homologs in the maize genome. These results revealed the molecular underpinnings of the low seed oil content in maize. In castor bean, we observed differential regulation of vital oil biosynthetic enzymes and extremely high expression levels of oil biosynthetic genes, which were consistent with the rapid accumulation of oil in castor bean developing seeds. Conclusions Compared to oil seed (rapeseed and castor bean), less oil biosynthetic genes were regulated during the seed development in non-oil seed (maize). These results shed light on molecular mechanisms of lipid biosynthesis in rapeseed, castor bean, and maize. They can provide information on key target genes that may be useful for future experimental manipulation of oil production in oilseed crops.

Combined Application of Citric Acid and Cr Resistant Microbes Improved Castor Bean Growth and Photosynthesis while it Alleviated Cr Toxicity by Reducing Cr+6 to Cr3+

Chromium is highly harmful to plants because of its detrimental effects on the availability of vital nutrients and secondary metabolites required for proper plant growth and development. A hydroponic experiment was carried out to analyze the effect of citric acid on castor bean plants under chromium stress. Furthermore, the role of two chromium-resistant microorganisms, Bacillus subtilis and Staphylococcus aureus, in reducing Cr toxicity was investigated. Different amounts of chromium (0 µM, 100 µM, 200 µM) and citric acid (0 mM, 2.5 mM, and 5 mM) were used both alone and in combination to analyze the remediation potential. Results showed that elevated amounts of chromium (specifically 200 µM) minimized the growth and biomass because the high concentration of Cr induced the oxidative markers. Exogenous citric acid treatment boosted plant growth and development by improving photosynthesis via enzymes such as superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase, which decreased Cr toxicity. The application of citric acid helped the plants to produce a high concentration of antioxidants which countered the oxidants produced due to chromium stress. It revealed that castor bean plants treated with citric acid could offset the stress injuries by decreasing the H2O2, electrolyte leakage, and malondialdehyde levels. The inoculation of plants with bacteria further boosted the plant growth parameters by improving photosynthesis and reducing the chromium-induced toxicity in the plants. The findings demonstrated that the combination of citric acid and metal-resistant bacteria could be a valuable technique for heavy metal remediation and mediating the adverse effects of metal toxicity on plants.

IDENTIFICATION OF Ricinus communis HYBRIDS FOR LOW PLANT HEIGHT1

ABSTRACT Castor bean (Ricinus communis L.) is a plant native to Africa that presents important socioeconomic value for many countries, and has been the subject of breeding programs. In this context, the objective of this work was to identify genotypes with potential for improvement, focused on lowering plant height, using 19 hybrids and eight parents of R. communis. The study was developed at the experimental area of the Federal University of Recôncavo da Bahia in Cruz das Almas, BA, Brazil. The experiment was conducted in 2017 using a randomized block design with three replications, consisting of eight parents and 19 hybrids resulting from hybridization of these parents, grown with spacing of 3 meters between rows and 1 meter between plants. The characters stem diameter (SD), primary raceme insertion height (PRI), number of stem internodes (NSI), mean stem internode length (SIL), plant height (PH), number of harvested racemes (NHR), primary raceme length (PRL), and effective raceme length (ERL) were evaluated by analyzing the genetic parameters of variances and correlation between them. Five (H17, H2, H11, H13, and H6) of the 19 hybrids evaluated have potential to decrease PH of castor bean plants, presenting heights below 1.07 m. Direct selection for plant height is the most indicated for this purpose due to the high heritability of the character. However, the characters SD, PRI, and SIL stood out by assisting in indirect selection to decrease plant height because they can be early measured and present high heritability and strong correlation with PH.