小麦低温基因型的研究现状和未来发展

 小麦低温基因型是一类具有偏低冠层温度（株温）的小麦,国内外已对它们的生物学特性及其在育种上的应用进行了20多年的研究并取得较大进展。研究证实自然界确有冠层温度偏低的小麦基因型存在;这些具有冷温特征的小麦基因型和其它一般小麦材料相比在一些重要生物学性状上占有优势,尤其代谢功能和细胞结构方面较为突出;在受到干旱、高温或连阴雨胁迫时,它们的一些重要性状的优势地位能够继续保持,具有广幅生态适应性;这些基因型的冠温所以偏低和第二热源温度偏低、植株活力较好密切相关;它们偏低的株温可以遗传,通过和其它小麦材料杂交,能对后代的温度状态产生较好影响,尤其小麦冷温供体——冷源的发现,更为产量又高又稳且质优质稳的小麦低温品种的培育创造了良好条件。小麦低温基因型的研究具有重要意义,其应用前途十分广阔。     

冷型小麦研究进展

通过多年来对小麦冠层温度和生物性状观测,结果发现自然界存在小麦温度分异现象,可将不同基因型小麦按冠层温度划分为冷型小麦、暖型小麦和中间型小麦等不同类群,这些类群的生物学性状有明显的差异,尤其在叶片输出功能期、根系活力、叶绿素含量、蛋白质氮含量、丙二醛含量、蒸腾速率和净光合速率等方面.冷型小麦在上述诸方面表现较优,即使在严重干旱和连阴雨等灾害性天气下也是如此.通过杂交试验表明,这些性状具有遗传性.又进一步从解剖学角度揭示冷型小麦和暖型小麦各器官在灌浆结实期的结构差异以及在干旱和淹水条件下冷、暖型小麦叶片结构的动态变化特征.     

鄂麦12品质性状的初步评价

对照国家专用小麦粉的行业标准,对高产小麦品种鄂麦１２的品质性状进行了初步评价,讨论了高产型小麦品种蛋白质含量偏低的生理原因。     

杂交春性小麦叶片衰老与保护酶系统活性的研究

 以常规小麦品种陕229为对照研究了强优势K型杂交春性小麦901叶片衰老与保护酶系统活性的关系。结果表明,在小麦灌浆前期2品种小麦叶片脂质过氧化产物MDA的含量都较低,质膜透性也较小。灌浆后期,常规小麦品种陕229脂质过氧化产物MDA的含量及质膜透性都极显著高于杂交春性小麦901。杂交春性小麦901酶促防御系统的保护酶SOD、POD、CAT活性高且相对稳定,清除代谢过程中产生的活性氧自由基的能力强,能较长时间的维持叶片细胞结构完整,合成充足的光合同化产物,使小麦的抗逆性增强,叶片衰老延迟,产量提高。     

抗旱小麦的冷温特性研究

选择 4种不同类型的小麦品种 ,通过测定功能叶片光合速率、群体冠层温度、叶片功能持续期 ,以及可溶性蛋白质、超氧化物歧化酶、丙二醛含量等指标 ,研究抗旱小麦的冷温特性。结果表明 ,在籽粒灌浆期间 ,抗旱小麦和冷型小麦的冠层温度持续偏低 ,它们的许多性状如叶片功能期、可溶性蛋白质含量、净光合速率、超氧化物歧化酶、丙二醛含量等明显优于暖型小麦和耐旱性差的小麦 ,在籽粒灌浆后期表现尤为明显。因此 ,在生产中 ,冠层温度可以作为衡量旱地小麦代谢功能的指标 ,并将为旱地小麦品系、品种的选择和高产栽培提供依据     

杂种小麦灌浆特点与粒重优势的研究

杂种小麦的粒重优势在利用杂交种提高小麦单产中具有重要意义,为了进一步研究杂种小麦荐灌浆特点及粒重优势,选用杂种小麦冀杂901和常规对照品种冀麦30作为试验材料进行了这方面研究,取得的主要结果报告如下:1)杂种小麦冀杂901灌浆过程、特点及其粒重超标优势形成的原因。将调查结果以花     

干旱条件下冷型小麦的生理特性分析

选择不同温型的小麦品种,通过测定群体冠层温度、叶片功能持续期以及丙二醛含量等参数,研究了干旱条件下冷型小麦的生理特性。结果表明,在籽粒灌浆期间,冷型小麦群体冠层温度持续偏低,其叶片功能期、蒸腾速率等性状明显优于暖型小麦品种,在籽粒灌浆后期表现尤为明显。冷型小麦对干旱的特殊适应性将为旱地小麦品系(种)的选择和高产栽培提供新的思路。     

黄淮南片“十一五”国审小麦品种品质性状分析

分析了＂十一五＂期间通过国家黄淮南片审定的40个小麦品种的品质性状。结果表明,黄淮南片小麦品种容重、蛋白质含量、湿面筋含量和吸水率数值较高,稳定时间、最大抗延阻力和拉伸面积数值偏低,即蛋白质数量性状较好,而蛋白质质量性状偏差。因此,黄淮南片小麦品质育种方面应该把主要的精力放在选育优质中筋小麦品种上,在有条件的地区适当发展强筋小麦,并加强小麦优质栽培技术的研究。     

杂种小麦部分品质性状的研究

研究了３种新型不育系选配的６个强优势组合的部分品质性状，并以当地大面积推广种植的优质小麦品种为对照，分析了杂种小麦的品质状况。结果表明，杂种小麦（组合）的品质性状因组合而异。６个杂种小麦的籽粒性状的平均值与对照纯系品种的平均值接近，有的杂种组合的容重略低于对照优质纯系品种。就蛋白质和湿面筋含量而言，有的组合接近或超过了对照优质小麦品种的平均值。面包烘烤实验的结果也表明，有的杂种小麦如Ｖｅｎ型杂交种９２Ｆ８３２８的品质性状比较突出。     

四川小麦新品种(系)的制曲品质性状评价

【目的】深入了解新育成小麦品种(系)的品质特征,筛选适宜酿造制曲的品种。【方法】以制曲小麦绵阳15和川麦41为对照,采用近红外仪对154份小麦的13个品质性状进行测定,同时采用硬度指数测定仪、凯氏定氮仪和淀粉试剂盒对筛选材料的硬度、蛋白质和淀粉含量等进行测定。【结果】156份小麦平均蛋白质含量12.48%,籽粒硬度55.09,软度179.17,除水分含量、吸水率和容重的变异系数小于10%外,其他性状变异较大;各品质性状间存在不同程度的显著或极显著相关;156份小麦根据品质特征可聚为7类,其中对照品种与120个品种(系)聚为一大类;所筛选的27份材料的平均总淀粉含量55.62%,直链淀粉含量22.02%。近红外测量与其他方法测量硬度(r=0.74)和蛋白质含量(r=0.88)显著正相关。【结论】156份小麦品质性状存在丰富的变异,主要属于中弱筋粉质小麦;绵阳15和川麦41存在品质差异,筛选出5份与对照品质相似的材料供进一步评价利用;研究所筛选材料为深入研究小麦品质与制曲品质关系奠定了基础。     

Grain Sink Strength Related to Carbon Staying in the Leaves of Hybrid Wheat XN901

XN901 is a K-type three-line hybrid wheat with a high yield potential, and its leaves and stem remaining green during grain maturation, suggesting much assimilate stay in leaves and stem. The grain water content, grain volume, carbohydrate content, and enzyme activity of sucose metabolism in the grain, as well as source-sink relationship were studied in order to investigate the physiological reason of the assimilate remaining in leaves and stem at the late stage. The results showed that the hybrid grains had more water and soluble sugar, higher activities of acid invertase and sucrose synthase at the early stage that led to a faster expansion growth, greater grain volume and faster starch synthesis at the early to mid stage of grain development. Also it had a longer period for actively filling. As a result, the grain weight and yield of the hybrid were increased by 14 and 15% respectively compared to that of Shaan 229. Additionally, the biomass of XN901 was 41.7% more than that of control, but its harvest index was 9% lower than Shaan 229. However, its lower activity of sucrose synthase indicated a lower sink activity at the late stage, resulting in a slow rate of filling and starch synthesis. Also, the hybrid wheat XN901 had a large source-sink ratio. It is the main reason for much assimilate remaining in the straw at the late stage and lower harvest index. Strengthening the sink activity and raising the harvest index should be the key means of improving the yield of hybrid wheat.     

小麦冷源及其性状特征的研究

 多年试验研究表明 ,自然界存在小麦冷源 ,它是一种冷温供体材料 ,有较强的降温作用 ,当受体小麦接受冷温供体的配子后 ,其后代冠层温度呈普遍下降态势 ,且部分受体小麦的温度型可由非冷型转化为冷型 ,明显提高了代谢功能。小麦冷源和不具有供冷能力的一般小麦相比 ,不但小麦群体第二热源温度及本身的体温偏低 ,且在根系活力、麦芒衰败速率、叶片功能期以及叶片的叶绿素含量、可溶性蛋白质含量、超氧化物歧化酶活性、净光合速率等方面均具有鲜明特点 ,这为小麦冷源的识别和选择提供了一定的生态生理依据。     

Study on Wheat Cold Source and Its Characters

On the basis of tests and studies for many years, wheat cold source has been discovered in natural world. It is a donor material supplying a low temperature and causing stronger cooling effect, that is,the canopy temperature of its progeny can be descended universally and some non-cold type acceptor wheat can turn into cold type wheat having good metabolic functions under the condition of that acceptor wheat accepts the gamete of donor wheat supplying a low temperature. Contrast between wheat cold source and general wheat having no the ability of supplying a low temperature shows that second heat source temperature and plant temperature of wheat cold source not only are lower than those of general wheat but its root vigor, rate of awn etiolation, functional duration of leaf, chlorophyll content, soluble protein content, SOD activity, net photosynthetic rate, etc, are also more excellent than those of general wheat, and these all provide certain ecological and physiological bases for the distinction and selection of wheat cold source.     

Research Status Quo and Future of Low Temperature Wheat Genotypes

Low temperature wheat genotypes are a group of wheat with a slightly low canopy （plant） temperature, and the research on their biological characters and utilization in wheat breeding has been done at home and abroad for more than 20 years, and has made great progress. The research contents and advances include the following respects： Wheat genotypes with slightly low canopy temperature have been verified to exist in nature; these wheat genotypes, which present cold temperature, are superior to conventional wheat materials in some important biological characters and particularly prominently in metabolic function and cellular structure; when they suffer stresses such as drought, high temperature and overcast and rainy weather, they still retain their superiority in some of their important biological characters and therefore have a wide range of ecological adaptability; slightly low canopy temperatures of these genotypes are closely correlated with low temperatures of their second heat sources and their vigorous plants; since their low canopy temperatures can be inherited, they can exert favorable influence on the temperatures of their offspring while crossing with other wheat materials, and in particular, the discovery of cold-source wheat as a contributor to low temperature, has further formed good conditions for breeding high and stable quality low temperature wheat varieties with a high and stable yield. Thus, low temperature wheat genotypes are of great research importance and have great prospects.     

K型杂交小麦901及亲本籽粒灌浆的生长分析

 为准确了解杂交小麦901的籽粒灌浆特性，用Matlab程序Richards 方程 对杂交小麦901及其亲本的籽粒灌浆资料用进行计算机拟合。结果表明，杂交小麦901籽粒活跃生长期比常规小麦陕229长约6 d，其最终粒重（43.7 g?1000粒-1）也比陕229（36.3 g?1000粒-1）高。杂交小麦和父本R205的N值均小于1，其灌浆前期籽粒生长迅速，中后期生长逐渐减慢。常规小麦陕229的N值大于1，灌浆前期生长较慢，中期生长迅速。从灌浆阶段的划分来看，杂交小麦901灌浆前期历时较短，中后期历时较长，而陕229与之相反。亲本中，父本R205的灌浆特性与杂交小麦901较相似，母本不育系K3314A却与陕229相似。用Richards方程拟合4个小麦品系的灌浆过程比用Logistic方程更适合。     

Effects of planting patterns plastic film mulching on soil temperature,moisture, functional bacteria and yield of winter wheat in the Loess Plateau of China

The yield of winter wheat is hindered by drought and low temperature in the Loess Plateau of China. Two common mulching methods to conserve soil moisture, ridge furrows with plastic film mulching (RP) and flat soil surfaces with plastic film mulching (FP) are helpful for wheat production. Our previous study indicated that FP could improve wheat yield more effectively than RP, but the reason remains unclear. The effect of mulching method on functional bacteria also needs to be further studied. In this study, winter wheat was employed to evaluate the impacts of mulching method on soil temperature, moisture content, microorganisms and grain yield. The results showed that FP had a warming effect when the soil temperature was low and a cooling effect when the temperature was too high. However, the ability to regulate soil temperature in the RP method was unstable and varied with year. The lowest negative accumulated soil temperature was found in the FP treatment, which was 20–89 and 43–99% lower than that of the RP and flat sowing with non-film mulching control (NP) treatments, respectively. Deep soil moisture was better transferred to topsoil for wheat growth in the FP and RP treatments than the NP treatment, which made the topsoil moisture in the two treatments (especially FP) more sufficient than that in the NP treatment during the early growing stage of wheat. However, due to the limited water resources in the study area, there was almost no difference between treatments in topsoil water storage during the later stage. The wheat yield in the FP treatment was significantly higher, by 12–16 and 23–56%, respectively, than in the RP and NP treatments. Significant positive correlations were observed among the negative accumulated soil temperature, spike number and wheat yield. The Chao1 and Shannon indices in the RP treatment were 17 and 3.9% higher than those in the NP treatment, respectively. However, according to network relationship analysis, the interspecific relationships of bacteria were weakened in the RP treatment. Phosphorus solubilizing, ammonification and nitrification bacteria were more active in the RP than in the FP treatment, and microbes with nitrate reduction ability and plant pathogens were inhibited in the RP treatment, which improved nutrient availability and habitat for wheat.