Identification and validation of cold responsive microRNAs of <Emphasis Type="Italic">Hevea brasiliensis</Emphasis> using high throughput sequencing

Cold stress is one of the major abiotic factors that influence the productivity and geographical distribution of many agriculturally important crops like Hevea brasiliensis. Cultivation of H. brasiliensis in India is being extended to northeastern regions, where low temperature during winter adversely affects its survival, growth, and productivity. Developing cold-tolerant genotypes is a primary requisite to maximize the productivity under such challenging environmental conditions. However, lack of methods for early evaluation of cold tolerance in the newly developed clones and the extensive time required for assessing their tolerance in the field are major constraints for clonal selection. The present study was initiated with an objective to identify and characterize cold stress responsive miRNAs from H. brasiliensis that show stronger association with cold tolerance. Next generation sequencing using Illumina HiSeq method revealed the expression of 21 and 29 conserved miRNA (from clone RRIM 600) families in cold-stressed and control samples, respectively. Forty-two novel miRNAs were identified from this study. Upon differential expression analysis, eight conserved miRNAs were found commonly expressed in both the samples. When expression analyses were performed subsequently with six selected miRNAs in two Hevea clones (viz. RRII 105 and RRIM 600), miR169 showed a strong association with cold tolerance. miRNAs such as miR482 and miR159 also exhibited association with cold tolerance. This study suggests the possibility of employing these miRNAs as markers for cold tolerance after validation in more number of genotypes with varying levels of cold tolerance.     

Lateritic and redoximorphic features in a faulted landscape near Manaus, Brazil

The soils and sediments of the uplands in the Manaus region are described and analysed along a representative cross‐section. There are two broad types of features, lateritic and redoximorphic. Their formation is linked to two main processes acting under contrasted hydrological regimes. The first process, acting under well‐drained conditions, is lateritization. It has transformed strongly weathered sediment into soil and led to depletion of silica (mainly quartz) as well as to relative accumulation of both kaolinite and iron oxides (haematite and goethite). Crystallographic changes observed in the latter have resulted from alternating dissolution and crystallization cycles without significant transfer of iron and alumina. However, in the uppermost soil, dissolution of kaolinite has prevailed over crystallization, leading to depletion of clay and the formation of tiny crystals of gibbsite disseminated throughout the groundmass. The second process results from the development of reducing conditions in groundwater giving redoximorphic features in lateritic soils and sediments. In the sediments, iron has been depleted by regional aquifers to form a pallid zone. In the soil, large amounts of iron and minor amounts of alumina, mainly from aluminous goethite, have been mobilized at first in small patches, which with further mobilization and vertical transfer of these elements have increased in size and have led to the formation of bleached horizons over thin iron pans. Iron has crystallized predominantly as haematite in the iron pans and alumina as large crystals of gibbsite in soil voids. Formation of impervious iron pans holds up fluctuating perched groundwater in the overlying horizons depending on rainfall events. Neotectonic events (formation of uplifted blocks and small grabens) have markedly altered the hydrological regimes. In the uplifted blocks, the soil has been deeply truncated and iron loss has been checked in the uppermost sediment. By contrast, mobilization of iron has been initiated at various places in the soil of the small grabens. In this way tectonic events have checked mobilization of iron in sediments but activated it in soils, leaving spectacular fingerprints on the landscape.     

Formation of Biogenic Amines and Associated Biochemical and Microbial Attributes of Whole Sutchi Catfish (Pangasianodon hypophthalmus) during Iced Storage

Sutchi catfish (Pangasianodon hypophthalmus) is a highly preferred farmed species that is produced in huge quantities. Meat from ice-stored (4 ± 2°C) whole Sutchi catfish was evaluated for formation of biogenic amines, such as putrescine, cadaverine, histamine (HIM), agmatine, tyramine, spermine, and spermidine, and compared with biochemical, microbial, and sensory attributes during 22 days. Analysis of content of biogenic amines in the meat was carried out by liquid chromatography with tandem mass spectrometry using a without derivatization method. Three amines, namely, tyramine, spermidine, and spermine, were only present on 0^th day of storage. Presence of cadaverine was noticed from 9^th day onwards, where the aerobic plate count (APC) reached 4.85 log CFU/g. Putrescine was detected on the 22^nd day of storage, where the APC crossed 7 log CFU/g. HIM was detected in lower quantities from 3^rd day onwards. A shelf life of 15 days was determined based on sensory and microbiological evaluation. Although the samples were biochemically acceptable throughout the storage period, APC exceeded the limit on day 19, and the gradual increase of H₂S-producing bacteria, Brochothrix thermosphacta, Aeromonas, and Enterobacteriaceae, was observed during storage.     

玉米秸秆水解残渣厌氧消化的产气性能

为了考察玉米秸秆水解残渣(Unhydrolyzed solid,UHS)的厌氧消化产甲烷潜力,研究了接种物类型、接种比例以及发酵温度对UHS产气性能的影响。结果表明,餐厨垃圾厌氧消化液作为接种物时,UHS具有较高的产气能力,累积甲烷产量达到208.06 m L·g~(-1)VS;UHS的累积甲烷产量与接种物对底物的比值(Inoculum to substrate ratios,RI/S)有关,其值随着接种比例的减小而逐渐降低,当接种比例RI/S为0.1∶1~3∶1时,累积甲烷产量为111.20~224.48 m L·g~(-1)VS,UHS的生物降解率为27.89%~56.29%,其降解能力随着底物浓度的升高而降低;在高温发酵(55℃)和中温发酵(35℃)条件下,相同接种比例的对照组中,UHS累积甲烷产量较为接近,但高温发酵的产气速率明显高于中温发酵。     

Expression of kit ligand and insulin‐like growth factor binding protein 3 during in vivo or in vitro development of ovarian follicles in sheep

Expression of Kit ligand (KL) and insulin‐like growth factor binding protein (IGFBP3) genes was studied at different in vivo and corresponding in vitro stages of development of the ovarian follicles in sheep. The expression of both KL and IGFBP3 was significantly higher in the primordial follicles relative to any other stage of development. Compared to the other stages, the KL expression in the cumulus cells from in vivo grown large antral follicles and that of IGFBP3 in COCs’ isolated from large antral follicles matured in vitro for 24 hr were significantly higher. In the oocytes from in vivo grown ovarian follicles, the expression of KL was the same at all the stages of development. Insulin‐like growth factor binding protein 3 expression was also the same in the oocytes at all the stages of the development except for a significantly lower expression in those from antral follicles. The expression of KL in the cumulus cells decreased significantly in the in vitro grown early antral follicles but did not change further as the development progressed. The expression of IGFBP3 in the cumulus cells from in vitro grown ovarian follicles appeared to increase as the development progressed although the increase was not significant between any two consecutive stages of development. In the oocytes in in vitro grown ovarian follicles, the expression levels of KL and IGFBP3 genes did not change with development. It is concluded that (i) KL and IGFBP3 genes follow specific patterns of expression during ovarian folliculogenesis and (ii) in vitro culture of preantral follicles compromises the development potential through alterations in the stage‐specific patterns of expression of these and other developmentally important genes.     

Damage pattern and status of the leaf miner Aphanisticus aeneus Kerremans (Coleoptera: Buprestidae) in Saccharum spp.

Biology, damage pattern, incidence levels and status of the leaf miner Aphanisticus aeneus Kerremans (Coleoptera: Buprestidae) were studied in accessions of Saccharum spp. Egg, grub and pupal periods of the miner lasted 6.0 ± 0.8, 18.5 ± 1.9 and 7.0 ± 1.3 days, respectively; adults lived for 8–10 days. The grub tunneled the leaf on the lower surface just above the epidermis forming a linear channel; infested tissues showed brownish discoloration. The extent of leaf miner attack among the 331 accessions of Saccharum spp. ranged 4.00%–76.47% on cane basis and 7.14%–100.00% on leaf basis; the mined leaf area ranged 3.22–11.00 cm². When the accessions were grouped on the basis of an infestation index developed with the above three parameters, 267 occupied very low category, 51 were in low category, 11 were in moderate category and 2 were placed in high incidence category. All accessions showed miner attack in at least one study year. Within each of the four Saccharum spp., accessions differed significantly among the three study years for all infestation parameters. Among the four species, while S. robustum accessions recorded significantly highest infestation index, the other three species remained on par.     

Effect of fast freezing then thaw‐aging on meat quality attributes of lamb M. longissimus lumborum

The objective of this study was to determine the effect of two different freezing rate then thaw‐aging regimens on the quality attributes of lamb loins. The loins were randomly allocated to one of five different freezing/thawing/aging regimes: fast‐(FF1A0) and slow‐(SF1A0) frozen only; fast‐(FF1A2) and slow‐(SF1A2) frozen then thaw‐aged for 14 days; aged for 14 days never frozen (A2). FF1A2 samples had a significantly higher water‐holding capacity compared to the slow frozen regardless of further aging periods. FF1A2 samples had lower (p < 0.05) shear force values than A2 and higher (p < 0.05) water‐holding capacity compared to the SF1A2. Fast freezing resulted in more intracellular cryo‐damage, whereas slow freezing resulted in extracellular cryo‐damage. FF1A0 and SF1A0 samples had lower (p < 0.05) myofibrillar proteins degradation. This study demonstrated that fast freezing then thaw‐aging can result in an improved water‐holding capacity and tenderness through the minimization of extracellular ice crystal formation, reduction in purge and drip losses, and improved proteolysis in thawed lamb.     

Effects of electrical stimulation and pre‐rigor conditioning temperature on aging potential of hot‐boned beef M. longissimus lumborum

The objective of this study was to create various pH/temp decline rates in hot‐boned bull beef M. longissimus lumborum (LL) through a combination of electrical stimulation (ES) and pre‐rigor holding temperature. The relationship between the pre‐rigor interventions, the activities of µ‐calpain and small heat shock proteins (sHSP), and the impacts on meat product quality were determined. Paired LL loins from 13 bulls were hot‐boned within 40 min of slaughter, immediately ES and subjected to various holding temperatures (5, 15, 25, and 35°C) for 3 hr. The rate of muscle pH decline, sarcomere length, shear force, and proteolysis of muscle proteins were measured. ES‐25°C had a longer sarcomere length compared to non‐electrical stimulation samples. ES‐25°C and ES‐35°C samples had lower shear force values, higher µ‐calpain activity and higher desmin, troponin‐T, and sHSP degradation. The above findings suggest that pH/temp decline rates created in hot‐boned muscle impacted muscle protein proteolysis by increasing the activity of proteases and degradation of sHSP.