How temperature and aridity drive lignin decomposition along a latitudinal transect in western Siberia

Climate change drives a northward shift of biomes in high-latitude regions. This might have consequences on the decomposition of plant litter entering the soil, including its lignin component, which is one of the most abundant components of vascular plants. In order to elucidate the combined effect of climate and soil characteristics on the decomposition pattern of lignin, we investigated lignin contents and its degree of oxidative decomposition within soil profiles along a climosequence in western Siberia. Soil samples were collected from organic topsoil to mineral subsoil at six sites along a 1500-km latitudinal transect, stretching from tundra, through taiga and forest steppe to typical steppe. The stage of lignin degradation, as mirrored by decreasing organic carbon-normalized lignin contents and increasing oxidative alteration of the remnant lignin (acid-to-aldehyde ratios of vanillyl- and syringyl-units [(Ac/Al)_V and (Ac/Al)_S]) within soil horizons, increased from tundra to forest steppe and then decreased to the steppe. Principal component analysis, involving also climatic conditions such as mean annual temperature and aridity index, showed that the different states of lignin degradation between horizons related well to the activity of phenoloxidases and peroxidases, enzymes involved in lignin depolymerization that are produced primarily by fungi and less importantly by bacteria. The low microbial lignin decomposition in the tundra was likely due to low temperature and high soil moisture, which do not favour the fungi. Increasing temperature and decreasing soil moisture, facilitating a higher abundance of fungi, led to increased fungal lignin decomposition towards the forest-steppe biome, while drought and high pH might be responsible for the reduced lignin decomposition in the steppe. We infer that a shift of biomes to the north, driven by climate change, might promote lignin decomposition in the northern parts, whereas in the south a further retardation might be likely.     

Effect of Vermicompost in Media on Growth,Yield and Fruit Quality of Cherry Tomato (Lycopersicon esculentun Mill.) Under Net House Conditions

Effects of VC application on tomato production and media properties can last for the third successive season, which was verified in this study to evaluate effects of VC application on growth, productivity and fruit quality of cherry tomato for the third season. Six treatments were designed similarly in the first and second seasons (unchanged design compared to the previous season), including: VC with rice husk ash (RHS) and coconut fiber (CF) 0% VC+ 50% RHS +50% CF (T1- control), respectively. 20%VC + 40% RHS + 40% CF(T2), 40% VC+ 30% RHS + 30% CF(T3), 60% VC + 20% RHS + 20% CF(T4), 80% VC + 10% RHS + 10% CF(T5), and 100% VC(T6). The results showed that the pH, EC, N, P, K, Ca, and Mg available in media were increased with the addition of VC. This finding revealed that the addition of VC significantly improved the physic-chemical media properties, increasing the EC and also increasing the macronutrients in the media resulting in substantial increased the yield and quality of tomato fruits. It is concluded that EC of VC was the key factor for the positive increase of the productivity and quality of tomato and the salinity (EC at 3.52 dS/m) causing restriction of water to fruits that resulted in the increase of the total soluble solids in tomato fruit and without affecting yield reduction.     

In vitro development of OPU‐derived bovine embryos cultured either individually or in groups with the silk protein sericin and the viability of frozen‐thawed embryos after transfer

The optimization of single‐embryo culture conditions is very important, particularly in the in vitro production of bovine embryos using the ovum pick‐up (OPU) procedure. The purpose of this study was to examine the development of embryos derived from oocytes obtained by OPU that were cultured either individually or in groups in medium supplemented with or without sericin and to investigate the viability of the frozen‐thawed embryos after a direct transfer. When two‐cell‐stage embryos were cultured either individually or in groups for 7 days in CR1aa medium supplemented with or without 0.5% sericin, the rates of development to blastocysts and freezable blastocysts were significantly lower for the embryos cultured individually without sericin than for the embryos cultured in groups with or without sericin. Moreover, the rate of development to freezable blastocysts of the embryos cultured individually with sericin was significantly higher than that of the embryos cultured without sericin. When the frozen‐thawed embryos were transferred directly to recipients, the rates of pregnancy, abortion, stillbirth and normal calving in the recipients were similar among the groups, irrespective of the culture conditions and sericin supplementation. Our findings indicate that supplementation with sericin during embryo culture improves the quality of the embryos cultured individually but not the viability of the frozen‐thawed embryos after transfer to recipients.     

Estimation of the standardized ileal digestible lysine requirement and optimal sulphur amino acids to lysine ratio for 30–50 kg pigs

Two experiments were conducted to determine the standardized ileal digestible (SID) lysine (Lys) requirement and the ideal SID sulphur amino acids (SAA) to Lys ratio for 30–50 kg crossbred pigs. In experiment 1, a total of 72 crossbred pigs with an average initial body weight (BW) of 28.9 kg were allotted to one of six dietary treatments in a randomized complete block design. Each diet was assigned to six pens containing two pigs each. Six diets were obtained by supplementing graded levels of L‐Lysine?HCl to create six dietary levels of SID Lys (0.70%, 0.80%, 0.90%, 1.00%, 1.10% and 1.20%). Responses of weight gain (ADG) and gain:feed (G:F) to increasing the SID Lys content of the diet fitted well with the curvilinear‐plateau model; whereas, for plasma urea nitrogen (PUN) two‐slope linear broken‐line model was well fitted. The optimal SID Lys requirement for the pigs of this period was 1.10%. Experiment 2 was a dose–response study using SID Met+Cys to Lys ratios of 50%, 55%, 60%, 65%, 70% and 64%. A total of 72 crossbred pigs with initial BW of 32.9 kg were randomly allotted to receive one of the six diets. Diets 1–5 were formulated to contain 1.0% SID Lys to be second limiting in Lys and diet 6 contained 1.11% SID Lys to be adequate in Lys. The average optimal SID SAA:Lys ratio for maximal ADG and G:F and minimal PUN was 65.2% using curvilinear‐plateau and linear broken‐line models.