Cutting as a method of breaking dormancy in microtubers producedin vitro

Microtubers formedin vitro often undergo long periods of dormancy. A simple method of promoting sprouting is to cut the microtubers in half. The promotive effect is demonstrated over a wide range of cultivars.     

Biofunctionalised polycaprolactone fibrous mat as a transfer tool for cell sheet engineering

Cell sheet technology is a unique technique in tissue engineering where cell sheets are generated from thermoresponsive substrates, by simple variation of temperature. Though the cell sheets have intact cell-cell and cell-extra cellular matrix junctions, the transfer of large sheets needs a carrier or transfer tool to prevent it from rolling and folding. In this study polycaprolactone electrospun mats with porous fibers (PPCL) functionalized with thrombin is proposed as a cell sheet transfer tool. The biofunctionalised mats were evaluated for cytocompatibility and analyzed for its efficiency to form a clot when exposed to blood plasma. This property was utilized to use the mats for cell sheet engineering. The efficacy of the biofunctionalised mat as a carrier was successfully demonstrated in the transfers of human lung epithelial and mouse fibroblast cell sheets generated from a thermoresponsive N-Isopropylacrylamide-co-Glycidylmethacrylate substrates. The clot acts like a sacrificial adhesive between the cells and the mat making the later to be used as a carrier tool in cell sheet engineering.     

In vitro mass tuberisation as a contribution to potato micropropagation

Summary Mass tuberisation was obtained on plantlets growing from nodal potato cuttings cultured in vitro on Murashige-Skoog (MS) medium under continuous light of 5000 lux at 24–25°C. Tuber formation was stimulated by transferring the plantlets to MS or White-Nitsch-Morel (WhNM) liquid or solid media supplemented with 8% sucrose, 2 mg 1⁻¹ benzyladenine (BAP), 2 mg 1⁻¹ naphthalenacetic acid (NAA) and/or 100 mg 1⁻¹ (2-chloroethyl) trimethylammonium chloride (CCC). Liquid media invariably induced heavier minitubers (390–790 mg each). The process to tuberisation took only two months. Minitubers always produced normal growing plants after dormancy break.     

Effect of changing coating process parameters in the preparation of antimicrobial-coated silk sutures: An in vitro study

Braided silk sutures were coated using a combination of poly(ε-caprolactone) (PCL) and sulfamethoxazole trimethroprim (SMZ) to investigate their antimicrobial performance. SMZ (2500 μg/ml) was combined with different PCL concentrations, i.e., 2.5 %, 5 %, 7.5 %, and 10 % (w/v). Antimicrobial test results showed that SMZ and PCL-treated silk sutures exhibited increasing antimicrobial efficacy against Gram-negative (Escherichia coli) and -positive bacteria (Staphylococcus aureus) with increasing PCL concentrations. The tensile and knot strength of sutures coated with 10 % PCL were significantly higher than those of sutures coated with 7.5 %, 5 %, and 2.5 % PCL. Treatment with PCL exhibited a positive effect on drug release from the sutures. Significant traits of antibacterial activity were observed up to 4 days after instalment of 10 % PCL-coated silk sutures. Under a scanning electron microscope, untreated silk sutures showed a surface heavily coated with bacteria, whereas treated sutures showed a smooth surface without bacteria. The results of this study indicate that SMZ combined with high concentrations of PCL may afford a suitable antibacterial coating agent for braided silk sutures.     

Serial microtuber formation as a long-term conservation method forin vitro potato germplasm

Microtubers were produced from single nodein vitro cuttings on 43 clonal potato cultivars and selections and two wild species. The microtuberforming cultures were exposed to three temperature regimes over a period of 21 months. At 10 C, cultures continued to produce microtubers after 21 months without subculture or supplementation of the media. Cultures of these single node axillary buds produced an average of 3.3 microtubers each after 21 months. This technique should be very useful in long-term storage of potato germplasm.     

Bovine faeces as a source of micro-organisms for the in vitro digestibility assay of forages

The aim of this study was to investigate whether bovine faeces could replace rumen liquor collected from fistulated sheep in the determination of organic matter digestibility (OMD) of forages in vitro . The first experiment compared two inocula that had been prepared by mixing 83 and 333 g of cattle faeces with 1 litre of artificial saliva according to the first stage of the in vitro technique of Tilley and Terry ( Journal of the British Grassland Society, 18, 104–111, 1963). Inocula made from 333 g of faeces gave higher values of OMD than that prepared from 83 g of faeces and was used in subsequent studies. When a 48-h acid pepsin digestion, the second stage of the Tilley and Terry (1963 ) technique, was included, the OMD values and the ease of filtering of undigested residues were increased. The second experiment compared digestibility determined with inocula produced from faeces with that produced from rumen liquor. The OMD of a ryegrass hay determined with an inoculum prepared from faeces was 0·468 compared with 0·528 when using an inoculum prepared from rumen liquor. The third experiment investigated the accuracy of estimating the OMD of eight contrasting forages determined using rumen liquor from three sheep ( y ) and faeces from two cows ( x ). All regressions were significant ( P  < 0·001) and had residual standard deviations (r.s.d.) of between ±0·019 and ±0·022. The final study compared faeces collected from cattle fed with either hay or concentrates. The OMD of forage was higher from the hay-fed animals, but the r.s.d. values of the regressions were similar. It was concluded that cattle faeces shows potential as an alternative to rumen liquor collected from rumen-fistulated sheep for use in the in vitro digestibility assay of forages.     

Diversity of condensed tannin structures affects rumen in vitro methane production in sainfoin (Onobrychis viciifolia) accessions

Sainfoin is a non‐bloating temperate forage legume with a moderate‐to‐high condensed tannin (CT) content. This study investigated whether the diversity of sainfoin accessions in terms of CT structures and contents could be related to rumen in vitro gas and methane (CH₄) production and fermentation characteristics. The aim was to identify promising accessions for future investigations. Accessions differed (P < 0·0001) in terms of total gas and CH₄ productions. Fermentation kinetics (i.e. parameters describing the shape of the gas production curve and half‐time gas production) for CH₄ production were influenced by accession (P ≤ 0·038), but not by PEG. Accession, PEG and time affected (P < 0·001) CH₄ production, but accession and PEG interaction showed only a tendency (P = 0·08). Increase in CH₄ due to PEG addition was not related to CT content. Further analysis of the relationships among multiple traits (nutritional composition, CT structure and CH₄ production) using principal component analysis (PCA) based on optimally weighted variables revealed differences among accessions. The first two principal component axes, PC1 (57·6%) and PC2 (18·4%), explained 76·0% of the total variation among accessions. Loading of biplots derived from both PCAs made it possible to establish a relationship between the ratio of prodelphinidin:procyanidin (PD:PC) tannins and CH₄ production in some accessions. The PD:PC ratio seems to be an important source of variation that is negatively related to CH₄ production. These results suggested that sainfoin accessions collected from across the world exhibited substantial variation in terms of their effects on rumen in vitro CH₄ production, revealing some promising accessions for future investigations.     

Interrelationship between ascorbic acid and gonadal hormones as determined in vitro

Summary 1. The effects of ascorbic acid on uterine motility vary according to the condition of the uterus and to the hormone treatment to which it has been subjected.2. The antagonism between oestradiol on one hand, and progesterone and testosterone on the other has also been proved, using ascorbic acid in vitro.     

Influence of flavonols as in vitro on low density lipoprotein glycation

INTRODUCTION: The non-enzymatic glycation of Low density lipoprotein (LDL) is a naturally occurring chemical modification of apolipoprotein B as a result of condensation between lysine residues and glucose. Glycated LDL is poorly recognized by LDL receptors and initiates different processes that can be considered proatherogenic. Thus, LDL glycation may contribute in the increased atherosclerotic risk of patients with diabetes. The objective of this study was to investigate the effect of naturally occurring flavonols on LDL glycation in vitro. METHODS: In this study, LDL was isolated from EDTA-plasma by ultracentrifugation using a single step discontinuous gradient. Then, glucose was added to LDL and LDL glycation level was estimated in absence and presence of flavonols by sodium periodate assay. RESULTS: This study was showed that five flavonols: quercetin, myricetin, kaempferol, rutin and morin decreased LDL glycation in a dose-dependent manner. Also, it was demonstrated this nutrients decreased electrophoretic mobility of glycated LDL. CONCLUSION: The results of this investigation show that flavonols probably with their antioxidant properties inhibited LDL glycation and thus may have a role in ameliorating atherosclerotic risk of patients with diabetes mellitus.     

Physicochemical studies using amylose as an in vitro model for resistant starch

The effects of hydrolysing amylose gels and films with porcine pancreatic alpha-amylase were studied in order to construct an in vitro model of resistant starch. Both gels and films proved to be partially resistant to hydrolysis, their susceptibility decreasing with increasing substrate concentration. Storage of gels for 1 day resulted in levels of crystallinity from 6 to 12%. Hydrolysis of these gels produced significant increases (from 272 to 557%) in crystallinity in all cases. The amount of resistant material remaining after hydrolysis increased (from 33% to 50%) with increasing gel concentration. Storage of amylose gels for 7 days resulted in levels of crystallinity of 28 to 35%. Hydrolysis of these gels led to increases in crystallinity, but to a lesser extent (from 148 to 175%) than before. The amount of resistant material remaining after hydrolysis increased (from 41 to 50%) with increasing gel concentration. Size-exclusion chromatography of resistant material from hydrolysed films indicated the presence of a high molecular weight component corresponding to undigested amylose, in addition to a low molecular weight component corresponding to partially digested amylose. Chromatograms of resistant material from both gels stored for 1 day and those stored for 7 days were almost identical and contained only a low molecular weight component with no sign of undigested amylose. X-ray line-broadening analysis showed the average sizes of the crystallites in the resistant material produced by hydrolysis of gels stored for both 1 day and 7 days to be approximately equal. The ability of the enzyme to diffuse into its substrate played a major part in the resistance to hydrolysis of amylose films, but had a much less important role in the resistance of gels. Not only crystalline, but also amorphous portions of amylose gels, were found to be resistant to enzymic hydrolysis. The resistant portion of amylose gels was modelled in vitro with a view to explaining the structure of resistant starch in vivo.     

亚麻—云南绿色经济的新支柱

本文阐述亚麻产业的光明前景,分析我国亚麻发展趋势,认为我国亚麻主产区南移将成事实,而云南在南方诸省中最具有发展亚麻的优势条件,因此将成为未来中国亚麻的生产中心,亚麻因此将成为未来云南绿色经济的新支柱。     

亚麻——云南绿色经济的新支柱

本文阐述亚麻产业的光明前景,分析我国亚麻发展趋势,认为我国亚麻主产区南移将成事实,而云南在南方诸省中最具有发展亚麻的优势条件,因此将成为未来中国亚麻的生产中心,亚麻因此将成为未来云南绿色经济的新支柱.     

Effects of olive oil mill wastewater used as irrigation water on in vitro pollen germination

The aim of this study is to assess the effects of Olive Oil Mill Wastewater (OOMW) application as irrigation water on in vitro pollen germination, focusing on total protein quantity. In test groups, pollen germination substances such as sucrose, H3BO3 and Ca(NO3)2 were added to different concentrations of OOMW and used as germination media. Regarding control group, the same substance melted into water instead of OOMW. As a result, in general, pollen germination percentage was decreased significantly in all OOMW concentrations than that of the control group, except 1/1000 concentrations. Similarly, total protein quantities declined linearly depending on decreasing OOMW concentrations, except 1/1 concentration which has 4-5 times the control value. Consequently, it was established that OOMW generally decreased pollen germination ratio and had carcinogenic effects on protein synthesis mechanism and must not be used as irrigation water without purification.     

Improving sink regulation,and searching for promising traits associated with hybrids,as a key avenue to increase yield potential of the rice crop in the tropics

Yield advantage of hybrid rice in the tropics has been reported recently as the result of higher biomass accumulation and better biomass partitioning over the whole crop growth. Considering that increasing biomass accumulation is the main target for higher yield potential in sub-tropical and temperate conditions, it is relevant to investigate in a wide range of growing conditions in the tropics if improved biomass partitioning plays a significant and consistent role in higher yield of hybrids. The growth pattern of two high-yielding and popular hybrid (H1) and inbred (I1) of the same maturity group was compared under six contrasted growing conditions to evaluate traits related to sink regulation. Grain yield of H1 was consistently higher than that of I1 by 16–32% with respect to the situation. Higher partitioning coefficients of the hybrid to key organs were confirmed over the whole crop growth for this set of environments whereas crop growth rates of hybrid were not consistently higher than that of inbreds. Sink strength index, as a way to express sink regulation at maturity more efficiently than harvest index, was higher with hybrids in five out of six environments. In search for promising traits related to sink regulation, higher specific leaf area of hybrids at very early stage was associated with higher leaf area, and earlier cessation of tiller production with hybrids coincided with higher partitioning of biomass to early culm growth: yet, maximum tiller number ranged from 548 to 962 tiller m⁻² with H1 and from 629 to 1427 tiller m⁻² with I1 while culm dry weight at 55 days after sowing ranged from 65 to 81 g m⁻² with H1 and from 46 to 53 g m⁻² with I1. This analysis strongly reinforced the pertinence of improving sink regulation for increasing yield potential in the tropics.     

马铃薯脱毒微型薯网室繁育技术

介绍了生产建设兵团农六师五家渠区域的马铃薯脱毒苗在网室繁育微型薯生产中的各个技术环节,重点是网室准备工作、试管苗移栽管理技术、水肥运筹、化学调控、病虫害防治及微型薯保存等技术措施,总结出一套行之有效的马铃薯脱毒微型薯网室繁育技术,以供同行参考。     

Validation of the Rostock fermentation test as an in vitro method to estimate ensilability of forages using glass jar model silages as a basis for comparison

This study compared the predictive power of an in vitro fermentation test [Rostock fermentation test (RFT)] with common glass jar silages (GLASS) using maize, fresh and wilted perennial ryegrass and fresh and wilted lucerne. Treatments were made in quadruplicate and included a control variant without additives, sucrose (20 g kg^?1), a homolactic inoculant (Lactobacillus plantarum, 3 × 10⁵ cfu g^?1), a heterolactic inoculant (Lactobacillus buchneri, 1 × 10⁵ cfu g^?1) and combinations of each inoculant with sucrose. The pH was measured in GLASS at days 1·5, 3, 10 and 90, and in RFT at 14, 18, 22, 26, 38 and 46 h, whereas fermentation products were determined at days 3 and 90 in GLASS, and at 46 h in RFT. Linear regressions revealed the closest relation for pH between 10‐d silages of GLASS and 38‐h measurement of RFT (adjusted R² = 0·808) and coefficients of determination for fermentation products were always higher when 3‐d instead of 90‐d silages were compared with 46‐h measurement of RFT. A pH increase in GLASS as indicator of insufficient anaerobic stability was not reproduced by RFT, suggesting that the in vitro test reflects the initial phase of fermentation, which was also indicated by the absence of 1,2‐propanediol in RFT.