Effect of Soil Moisture on Relative Leaf Water Content, Chlorophyll, Proline and Sugar Accumulation in Wheat

The responses of four wheat ( Triticum aestivum L.) varieties to soil moisture were determined by measuring plant parameters such as relative leaf water content (RLWC) and the chlorophyll, proline and sugar contents of the leaf over two seasons. Two levels of irrigation treatments were adopted: irrigated and rainfed. The rainfed plants had consistently higher amounts of proline and sugar but lower RLWC and chlorophyll content. As drought intensified, differences between the irrigated and the rainfed plants with respect to all of these characters increased. The RLWC values of the irrigated plants were significantly higher in the morning but lower values were found at noon, showing some recovery in the afternoon.     

不同基因型小麦初生根和次生根生长及生理差异

通过盆载和管栽小麦试验分析，总根系１初生根和次生根的生长及根中呼吸存在基因型差异。早硎一根前期发育快，后期衰退也快；晚熟基因型则相反，但极量的多少并不直接影响产量。     

提高北方寒地冬小麦越冬率机制初探

在黑龙江省北纬Ｎ４６～４８°区域试种冬小麦，五年试验表明，以高越冬率为指标，分蘖节处于可溶性糖等光合产物峰值区的分蘖盛期，为抗寒的最佳状态，分蘖盛期分蘖节可溶性糖含量的高低，亦可为品种抗寒性选择的评价尺度。由于根前区对低温比分蘖节更为敏感，使冬小麦根前区位于温度和对稳定的３０ｃｍ地层以下，应是采取适当栽培的调控措施的目的。     

Estimation of protein contents in winter wheat grain using satellite remote sensing

(Jpn. J. Soil Sci.Plant Nutr., 77, 317–320, 2006)     

Nitrogen application method for improving yield and protein content of “Kitanokaori”, a new variety of winter wheat for bread use in Hokkaido

(Jpn. J. Soil Sci.Plant Nutr., 77, 273–281, 2006)

“Kitanokaori” is a new variety of winter wheat (Triticum aestivum L.) for bread use bred at the National Agricultural Research Center for Hokkaido Region. The grain protein content of wheat for bread use should be higher than 120 g kg?1. Much nitrogen application is necessary to obtain high grain protein content. Therefore, it is necessary to determine the optimum amount of nitrogen to obtain the required protein content and to prevent nitrogen from remaining in the soil. Field experiments were conducted for four years from sowing in 2000 to study the effect of the amount of nitrogen and the time of top-dressing. In the experiment in which sowing was carried out in 2003, nitrogen treatments were 40, 40–60, 40–60–0–60, 40–60–0–60–30, 40–60–0–60–60, 40–60–60–60, 40–60–60–60–30, 40–60–60–60–60, 40–60–30–30, 40–60–30–30–30 and 40–60–30–30–60 (each value showing the amount of applied nitrogen at sowing · re-growing stage · panicle formation stage · flag leaf stage · full heading stage, kg ha?1). The experiments were conducted in Andosol, which has moderate nitrogen fertility, and in Histosol, which is fertile soil.

Kitanokaori did not lodge with high-applied nitrogen, and both yield and protein content increased with an increase in applied nitrogen. In a moderate climate, Kitanokaori reached a protein content of 120 g kg?1 when the amount of absorbed nitrogen was about 190 kg ha?1, and the yield was about 7·8 Mg ha?1 at that time.

The top-dressing at the panicle formation stage was effective to raise the yield and the top-dressing at the full heading stage was effective to raise the grain protein content. It is recommended that the amount of applied nitrogen should be 160 kg ha?1 until the flag leaf stage, and additional nitrogen should be applied at the full heading stage to obtain a grain protein content of more than 120 g kg?1. Nutritional diagnosis at the full heading stage will be necessary to determine whether more nitrogen is needed to achieve the required protein content.

When the amount of total applied nitrogen did not exceed 220 kg ha?1, the amount of absorbed nitrogen was over 90% of applied nitrogen, and there was little inorganic nitrogen in the soil after harvest. Therefore, it was considered that the residue of nitrogen in the soil was small within 220 kg ha?1 of nitrogen application, while favorable growth and high yield were obtained.     

2006-2007年小麦新品系选拔试验

通过对36份小麦品系比较试验,调查了小麦的株高、有效穗数、成熟期、穗长、结实小穗、实粒数、单穗重、千粒重等性状,并进行了聚类分析.结果表明:36份品系可分成5种类型,第1种为粒少、低产类型;第2种为穗少、低产类型;第3种为粒多、穗多、高产类型;第4种为穗多、粒多、粒大、高产类型;第5种为晚熟类型.     

Wheat Seed Presoaking for Improved Germination

Seed presoaking improves wheat germination under marginal moisture conditions. The duration of seed presoaking was studied at The University of Arid Agriculture, Rawalpindi, using 10 wheat varieties. Seed presoaking beyond 12 h does not improve germination further, and beyond 21 h, germination rate is drastically reduced.     

青莜麦双季栽培和麦茬复种技术的研究

青莜麦不同品种和播期的试验结果表明:第一季青莜麦比第二季晚熟品种的株高、叶面积系数均高;品种323和82的单季产草量达87544.5kg/hm2和85042.5kg/hm2,双季比单季增产68.0%~81.2%。麦茬复种青莜麦产草量达64500~67500kg/hm2;并以7月20日为最佳播种期,比其他播期增产38.9%~77.0%。品种323籽粒产量3789.8kg/hm2,比对照增产26.3%~66.7%,其粗蛋白质、粗脂肪含量均比对照高;麦茬复种青莜麦比复种青玉米的粗蛋白质和粗脂肪含量高。选用品种323和82进行双季栽培或麦茬复种青莜麦,可取得显著的经济、社会和生态效益。     

壮丰安对冬小麦产量和产量器官发育的影响

以两个冬小麦品种京冬6号和农大142为材料,研究了新型植物生长调节剂-壮丰安对小麦产量器官的调控效应。结果表明:壮丰安处理调节了小麦穗的乙烯释放量和籽粒中 IAA,Z+ZR 等内源激素水平;加快了小麦籽粒乳熟中期以后的灌浆速度,可使穗数、结实小穗、穗粒数和穗粒重不同程度增加,表现一定的增产作用;收获后的种子经生物学方法测定,药效残留很少,正常施用对环境和产品安全。     

The Role of Phenolics and Peroxidase in Resistance to Alternaria triticina in Bread Wheat (Triticum aestivum L.)

Total phenolic content in eight diverse wheat lines showed that PF-70354 YACO'S' had the highest (802.90 ± 1.35 μg g⁻¹ fresh weight) and Agra Local possessed the lowest amount (684.72 ± 5.28 μg g⁻¹ fresh weight). However, for further experiments two lines namely, ACC-8226 and MP-845, with contrasting disease scores under field trials were assessed. Pre-infectional levels of total phenolics and peroxidase activity were higher in ACC-8226 than in MP-845. Furthermore, the amount of phenolics and peroxidase activity in each case increased after inoculation. The post-infectional levels of phenolics and peroxidase were again higher in ACC-8226 than in MP-845. The peroxidase activity decreased with age in both the varieties, with very little peroxidase activity after 35th day. However, the amount of phenolics started to decrease with the progress of disease and age in MP-845, whereas in ACC-8226 an elevated level of it was maintained. Our findings not only support that ACC-8226 is the resistant and MP-845 is the susceptible variety but also provide important biochemical parameters for plant breeders to authentically identify potential breeding material and plan effective breeding strategies using these tools.