Seasonal differences in freezing stress resistance of needles of Pinus nigra and Pinus resinosa: evaluation of the electrolyte leakage method

Seasonal changes in freezing stress resistance of needles of red pine (Pinus resinosa Ait.) and Austrian pine (Pinus nigra Arnold) trees were measured by an electrolyte leakage method and by visual observation. During most of the year, freezing stress resistance determined by the two methods gave similar results. The electrolyte leakage method provided a good estimate of seasonal changes in freezing stress resistance except for red pine needles in their most winter-hardy state. To obtain a reliable estimate of freezing stress resistance in winter-hardy red pine needles it was necessary to combine the electrolyte leakage method with visual observations. When red pine needles survived exposure to -80 degrees C or lower, electrolyte leakage was never more than 30% even when the needles were exposed to a slow freeze-thaw stress of -196 degrees C. However, rapid freezing of red pine needles to -196 degrees C resulted in electrolyte leakage of over 80%. Red pine needles attained a much higher freezing stress resistance during the winter than Austrian pine. Red pine needles also acclimated and deacclimated faster than Austrian pine needles. An index of injury was developed based on the electrolyte leakage method ((R(2) + R(1))/2, where R(1) is the minimum % electrolyte leakage from noninjured tissue and R(2) is the maximum % electrolyte leakage at the highest injury) that reliably predicted freezing stress resistance of pine needles for most of the year. Important aspects for developing a successful index of injury for pine needles are: use of cut needles, vacuum infiltration and shaking during incubation in water.We conclude that: (1) during cold acclimation the cell wall properties of the pine needles changed and these changes, which appeared to differ in the two species, might explain the very low leakage of electrolytes from winter-hardy needles of red pine; (2) pine needles survive winter by developing the ability to tolerate extracellular ice formation, because after rapid freezing the needles were severely injured; and (3) red pine is adapted to a shorter growing season and colder winters than Austrian pine.     

Measurement of soil waterlogging tolerance in Phaseolus vulgaris L.: A comparison of screening techniques

Three methods not reported previously to determine flooding tolerance, and a visual scoring system developed for this study, were utilized to evaluate the effects of soil waterlogging upon 3 bean genotypes empirically differing in tolerance. These methods consisted of: (1) Triphenyl Tetrazolium Chloride Reduction Method (TTC), which measures flooding tolerance by determining the rate of root respiration during stress; (2) Electrical Conductivity Method (EC), in which the degree of root cell membrane integrity is determined; and (3) Pressure Chamber Method (PC), by which the degree of plant desiccation is found by measuring the water potential of the xylem. A visual scoring method based on the external appearance of the plant was also used. The agreement among methods was generally good. The TTC and EC methods were more time-consuming and results more variable, especially from the latter. Results of the PC and visual scoring methods were highly correlated (r=0.85). However, TTC and EC required only 7-day-old seedlings, thus allowing the screening of large numbers of samples and the efficient use of space. The F₁ and F₂ progeny from crosses between the most tolerant genotype (P074) and the most sensitive genotype (P149) indicated that differences in reaction to flooding are probably heritable.     

Fine screening potato (Solanum) species germplasm for tuber calcium

A representative sample of the US potato germplasm collection was screened in the greenhouse for ability to accumulate tuber calcium. Germplasm with very high and very low calcium accumulation capacity has been identified by progressively screening for extremes among species, among populations (accessions), and finally among genotypes (i.e., fine screening). Among accessions, the bestS. gourlayi andmicrodontum populations averaged more than six-fold greater tuber calcium than the poorestS. kurtzianum population. When screening was performed at the genotype level, the best individuals ofgourlayi andmicrodontum had over eight-fold greater calcium than the poorestkurtzianum individual. When grown in the field, calcium levels ofS. microdontum selections were confirmed to be significantly higher thantuberosum cultivars. When selected genotypes were intercrossed and their progeny were compared to their original populations, mean tuber calcium was significantly changed in the intended direction of selection forS. kurtzianum (made lower) andS. microdontum (made higher). These stocks are expected to be useful tools for study of the genetic and physiological bases of tuber calcium accumulation, refining screening methods, and breeding improved cultivars.     

Growth and reproductive performance of sambar deer in Sabal Forest Reserve of Sarawak, Malaysia

We examined the growth, reproduction, rutting behavior, and health status of sambar deer (Cervus unicolor brookei) in secondary Acacia mangium plantation. The data were collected over 11 years from a breeding herd of 21 stags and 33 hinds in Sabal Forest Reserve, Sarawak, Malaysia. Brody’s growth model of the pooled data is Y _t ?=?148.56 (1???0.98e^?0.023t ), which estimates that maximum weights of adults are 184 and 115 kg for males and females respectively. Sambar deer are nonseasonal breeders with the breeding peak in February. Although the earliest age at which a female reached sexual maturity was 11 months, the mean age was 23?±?7 months. Mean age of first fawning was 32?±?8 months. Mean gestation period was 259?±?12 days (n?=?82). Stags shed antlers mostly between March and July. Velvet hardens at 103?±?27 days (n?=?23), and velvet harvesting is best at 7–9 weeks when antler length is 25–30 cm. Sambar deer are suitable as a farm species in forest plantations and have a vast potential to uplift rural living standards.     

Effect of TGF‐β1 Superfamily Members on Survival of Buffalo (Bubalus bubalis) Embryonic Stem‐like Cells

This study examined the effects of supplementation of ES‐like cell culture medium with bone morphogenetic protein (BMP)‐4 (0, 10, 20 or 100 ng/ml) or Noggin (250, 500 or 750 ng/ml) or TGF‐β1 (0, 0.1, 1 or 10 ng/ml) or SB431542 (0, 10, 25 or 50 μm ), an inhibitor of TGF‐β1 signalling, on survival, colony area and expression level of pluripotency genes in buffalo ES‐like cells at passage 40–80, under different culture conditions. BMP‐4 supplementation significantly reduced (p < 0.05) colony survival rate, percentage increase in colony area and relative mRNA abundance of OCT4, whereas that of NANOG and SOX‐2 was increased significantly (p < 0.05). Noggin supplementation did not affect the colony survival rate and percentage increase in colony area in the presence of FGF‐2 and LIF. In the presence of FGF‐2 alone, it significantly reduced (p < 0.05) the relative mRNA abundance of OCT4 and SOX‐2 and increased (p < 0.05) that of NANOG. Supplementation with TGF‐β1 at 1.0 ng/ml but not at other concentrations increased colony survival rate but had no effect on percentage increase in colony area at any concentration. Supplementation with SB‐431542 decreased (p < 0.05) colony survival rate at 50 μm but not at other concentrations. The percentage increase in colony area was lower (p < 0.05) with 10 μm SB‐431542 than that in the controls, whereas at higher concentrations of 25 or 50 μm , SB‐431542 decreased (p < 0.05) the colony size instead of increasing it. In conclusion, these results suggest that BMP‐4 induces differentiation in buffalo ES‐like cells, whereas TGF‐β/activin/nodal pathway may not be playing a crucial role in maintaining pluripotency in these cells.     

冷驯化前后野生马铃薯Solanum acaule内参基因的筛选

为找到表达稳定性最好的内参基因,利用实时荧光定量PCR技术分析了4个内参基因ef1-a、Actin、β-tubulin2和β-tubulin3在野生马铃薯S.acaule冷驯化前后的表达稳定性。结果表明:β-tubulin2和ef1-a表达均稳定,Actin变化最大。因此,β-tubulin2和ef1-a适宜作为野生马铃薯S.acaule的内参基因。     

Nutritional Requirement of Adult Donkeys (Equus asinus) during Work and Rest

Tropical Animal Health and Production -     

m‐carboxycinnamic acid bishydroxamide improves developmental competence,reduces apoptosis and alters epigenetic status and gene expression pattern in cloned buffalo (Bubalus bubalis) embryos

Incomplete or aberrant reprogramming of nuclear genome is one of the major problems in somatic cell nuclear transfer. In this study, we studied the effect of histone deacetylase inhibitor m‐carboxycinnamic acid bishydroxamide (CBHA) on in vitro development of buffalo embryos produced by Hand‐made cloning. Cloned embryos were treated with CBHA (0, 5, 10, 20 or 50 μM) for 10 hr from the start of reconstruction till activation. At 10 μM, but not at other concentrations examined, CBHA increased (p < .05) the blastocyst rate (63.77 ± 3.97% vs 48.63 ± 3.55%) and reduced (p < .05) the apoptotic index of the cloned blastocysts (8.91 ± 1.94 vs 4.36 ± 1.08) compared to untreated controls, to levels similar to those in IVF blastocysts (4.78 ± 0.74). CBHA treatment, at all the concentrations examined, increased (p < .05) the global level of H3K9ac in cloned blastocysts than in untreated controls to that observed in IVF blastocysts. Treatment with CBHA (10 μM) decreased (p < .05) the global level of H3K27me3 in cloned blastocysts than in untreated controls but it was still higher (p < .05) than in IVF blastocysts. CBHA (10 μM) treatment increased (p < .05) the relative expression level of pluripotency‐related genes OCT‐4 and NANOG, and anti‐apoptotic gene BCL‐XL, and decreased (p < .05) that of pro‐apoptotic gene BAX than in untreated controls but did not affect the relative expression level of apoptosis‐related genes p53 and CASPASE3 and epigenetics‐related genes DNMT1, DNMT3a and HDAC1. These results suggest that treatment of cloned embryos with 10 μM CBHA improves the blastocyst rate, reduces the level of apoptosis and alters the epigenetic status and gene expression pattern.