芝麻种子发育过程中脂肪酸积累模式的研究

以中熟品种鄂芝２号为材料对芝麻种子发育过程中脂肪酸的累积过程进行了分析。分析显示,芝麻种 子发育早期有７种脂肪酸,成熟期减少为４种。成熟期的种子亚油酸和油酸占全部脂肪酸的８０％以上,亚麻酸和 棕榈亚油酸发育中途消失。芝麻品种脂肪酸总量变化呈Ｓ形模式,脂肪酸总量达到峰值以后有一段显著回落,导 致含油量降低。鄂芝２号含油量回落时间出现在开花后３８ｄ左右。芝麻种子发育过程中油酸与亚油酸呈同步积 累,正相关极显著,在脂肪酸组成中具支配地位,推测ＦＡＤ２和ＳＡＤ两种酶在决定芝麻脂肪酸组成方面可能具有决 定性作用。     

籽用南瓜种子发育过程中脂肪酸积累模式的研究

以籽用南瓜品种银辉一号为材料对南瓜种子发育过程中脂肪酸的累积过程进行了分析。结果表明,成熟的南瓜种子中可检测到8种脂肪酸,按含量高低依次为：油酸、亚油酸、棕榈酸、硬脂酸、花生酸、豆蔻酸、棕榈油酸、亚麻酸。南瓜种子粗脂肪含量的积累模式呈现升-降-升的Z字型变化模式。在累积过程中除了C18:1和C18:3有负相关性外,其它脂肪酸相互之间显示了高度的正相关性。     

高低芥酸油菜品种发育籽粒脂肪酸积累模式的研究

以甘蓝型油菜低芥酸品种秦油7号和高芥酸品种中油821为材料,对油菜籽粒发育过程中主要脂肪酸的积累模式进行研究,并分析高低芥酸品种间脂肪酸积累的差异及各种脂肪酸之间的相关性。结果表明：根据7种主要脂肪酸在种子发育过程中的积累模式,可将它们分成两类：一类为棕榈酸、硬脂酸、亚油酸、亚麻酸,其积累主要集中在种子发育早期;而油酸、二十碳烯酸和芥酸可归为另一类,其积累主要集中在种子发育后期。两个品种在棕榈酸、硬脂酸、亚油酸、亚麻酸、油酸以及油份积累模式上基本一致,但在油酸、二十碳烯酸和芥酸的积累量上差异较大。     

不同品质类型花生籽仁脂肪酸积累规律研究

以高蛋白品系KB008、高脂肪品种花17和高油酸/亚油酸品种农大818为材料对花生籽仁发育过程中脂肪酸积累规律进行研究。结果显示,在花生籽仁发育过程中,籽仁中脂肪的积累速度呈先快后慢的趋势。油酸亚油酸比值(O/L)受遗传因素影响较大,收获期O/L值以农大818最高,KB008最低,差异显著。不同品种成熟期的脂肪酸组分相对含量存在差异,高蛋白品种成熟期亚油酸、棕榈酸、硬脂酸、花生酸和山嵛酸相对含量显著高于高脂肪和高O/L值品种,而其油酸和二十四烷酸相对含量明显低于后两者。高脂肪品种和高O/L值品种成熟期脂肪酸组分相对含量差异不明显。     

不同花生品种脂肪酸组成及其积累规律的研究

以15个花生品种(系)为研究材料,对其油脂含量和脂肪酸组成进行了比较分析。结果显示,所有花生品种(系)种子总油脂含量差异不大,平均为51.34%。主要检测到油酸、亚油酸、棕榈酸、硬脂酸、山萮酸、花生酸、花生烯酸、二十四烷酸8种脂肪酸,其中油酸含量最高,品系E1高达85.61%,品系E11的油酸含量最低,仅为37.12%。含量仅次于油酸的是亚油酸,含量在1.44%~37.11%之间,其中品系E11的亚油酸含量最高,品系E1含量最低。同时,选取其中4个品种(系)进行种子发育过程中油脂和脂肪酸含量变化规律的研究。结果显示,在种子发育过程中油脂含量持续积累,呈先快后慢趋势,部分品系在后期油脂含量略有下降。硬脂酸含量逐渐升高,棕榈酸含量逐渐降低。油酸含量的变化规律与亚油酸相反,说明油酸含量的增加可能由于生成亚油酸脂肪酸的减少。     

高含油量油菜种子和果皮油份积累及主要脂肪酸的动态变化

以高含油量油菜品系为材料,研究角果发育过程中种子和果皮油份积累与主要脂肪酸的动态变化。结果表明：高含油量品种在角果发育早期油份的合成与积累较为缓慢,开花后20d种子含油率仅占成熟种子油份含量的8.35%-12.32%,角果发育中期是油份含量增加最快的时期,开花后40d种子含油率占成熟种子油份含量的72.89%-94.73%,籽粒成熟时油份含量达到最大值。果皮的油份积累与种子相反,随角果发育油份含量依次下降,两者呈极显著负相关,相关系数为-0.95。种子和果皮的二十碳烯酸、芥酸合成规律明显不同。种子的7种主要脂肪酸组成中芥酸和二十碳烯酸与16碳、18碳脂肪酸含量均呈负相关,亚麻酸和亚油酸与棕榈酸、硬脂酸和亚油酸含量均呈正相关,与油酸含量H2和H27为正相关,H1和H28为负相关。而油酸与其它脂肪酸的相关关系较为复杂,与棕榈酸、硬脂酸和亚油酸、亚麻酸的相关关系有正相关,也有负相关,可见油酸的合成与积累不仅与棕榈酸、硬脂酸有关,还会影响亚油酸和亚麻酸的含量,这是创新油菜高油酸材料的基础。     

花生籽仁发育过程中脂肪酸积累规律研究

以高O／L花生品种8130为材料对其籽仁发育过程中脂肪酸的累积过程进行分析。结果显示,花生籽仁中,含有8种主要的脂肪酸,按含量高低依次为油酸、亚油酸、棕榈酸、硬脂酸、山嵛酸、花生酸、二十四烷酸、花生烯酸;花生籽仁发育过程中,油酸含量逐渐增多,其它脂肪酸呈逐渐降低的变化规律。饱满籽仁中亚油酸和油酸含量占全部脂肪酸的80％以上。脂肪酸总量在籽仁发育前期增加迅速,然后缓慢增长,到籽仁成熟期又迅速增加,在收获期达到峰值,油酸亚油酸比值（O／L）,随籽仁发育呈逐渐增加的变化规律,饱满籽仁达到最大。     

花生种子发育过程中脂肪酸累积模式研究

花生种子脂肪酸组成是决定花生油营养和储藏品质的关键因子。本文通过对花生种子脂肪酸累积模式的研究,揭示花生脂肪酸组成的形成规律。在开花结荚期和荚果成熟期每隔7天取材一次,果针入土后第7天第一次取材,对各个时期果仁进行脂肪酸分析,研究脂肪酸组成及积累规律;并对种子发育全过程的脂肪酸组成进行相关分析和主成份分析。研究结果显示,下针后10天内的花生种子可检测到9种脂肪酸,C16:1和C18:3在发育过程中由高到低,逐渐消失,其他7种脂肪酸则随着花生种子的发育逐渐积累增高。成熟的花生种子中油酸和亚油酸含量占脂肪酸总含量的81%左右。脂肪酸总量在接近成熟时有所下降。不同脂肪酸在累积过程中显示了高度相关性,C16:1和C18:3之间呈正相关,属于第一类;其余7种脂肪酸之间也均呈正相关,属于第二类。第一和第二类脂肪酸之间呈负相关。主成份分析表明,9种脂肪酸可以分成三类：C18:1与C18:2各为一类,其他7种脂肪酸为另一类,C18:1与C18:2之比是花生脂肪酸组成的决定性因素。通过分析表明,决定花生脂肪酸组成的关键基因主要是脂肪酸去饱和酶FAD2基因和SAD基因,有目的地对这两个基因的表达进行调控对于花生脂肪酸组成的改良有着重要的价值和意义。     

大豆内源基因调控与籽粒不饱和脂肪酸的形成

大豆亚油酸主要的合成途径是在大豆内源基因fad2调控下由油酸生成亚油酸.与此同时,在内源基因fad3作用下,亚油酸又部分转化成为亚麻酸.采用7个国内外具有一定代表性的栽培品种,对大豆籽粒成熟过程中不同时期的样本进行定量PCR分析.结果表明:不饱和脂肪酸的合成过程是一个连锁反应,单独一个基因的表达不但影响与其相关的代谢途径,而且连带影响其他脂肪酸成分的积累.fad3的高量表达,促进不饱和脂肪酸积累总量的增加.籽粒发育后期,油酸含量下降,亚油酸,亚麻酸含量稳步上升.当fad2表达受抑制时,亚油酸含量也较低.     

生殖生长期遮阴对大豆脂肪酸积累动态的影响

大豆脂肪酸组分及配比影响大豆油脂的营养价值和贮运加工环节,是决定大豆油脂品质的最重要因素.尽管品种的遗传特性决定着脂肪酸各组分含量高低,生态环境通过影响脂肪酸的积累动态,同样影响着脂肪酸的含量.以品质不同的3个大豆品种(系)为材料,研究了生长生殖期遮阴对大豆籽粒发育过程脂肪酸各组分积累动态的影响.遮阴显著降低了黑农35和垦农18成熟籽粒内的棕榈酸和硬脂酸的含量(降幅达1.51%),并显著升高了亚油酸的含量(升幅达2.02%);与此相反,遮阴升高了海339大豆成熟籽粒内棕榈酸和硬脂酸含量(升幅达1.01%),并显著降低了亚油酸含量(降幅达2.63%).与对照相比,遮阴升高了海339大豆成熟籽粒内油酸含量(升幅达2.01%),但降低了黑农35成熟籽粒内油酸含量(降幅达1.72%),对垦农18成熟籽粒内油酸含量无影响.遮荫对大豆各脂肪酸组分含量动态的影响,因大豆品质和脂肪酸组分的不同而各异.开花后30 d是遮阴影响大豆籽粒内各脂肪酸组分积累的关键期,表明大豆群体过早郁闭将影响到大豆脂肪酸的品质,应根据不同品质大豆脂肪酸积累的生理特性确定合理的群体栽培管理措施.     

THE EFFECT OF THE TIME AND LEVEL OF INJECTION OF ANHYDROUS AMMONIA ON THE PRODUCTIVITY OF GRASSLAND

Four levels of nitrogen, 188, 285, 358 and 392 kgJ.ha (150, 225, 285 and 350 units/ac) supplied as anhydrous ammonia were injected on each of four occasions, 18 Dec, 5 Feb., 12 Mar. and 16 Apr. DM and CP yields were estimated at each of three harvests taken on 4 June, 19 July and 28 Sept Total DM yields showed only a 10% difference between the highest yielding injection date, 12 Mar., which yielded 12270 kg/ha (10946 Ib/ac) and the lowest, 16 Apr., which yielded 11169 kgJ.ha (9963 Ib/ac). Early injection of ammonia promoted growth during the late spring and later injections resulted in increased yields at the two later harvests. The responses per kg fertilizer N were 11.9 kg DM (10.8 lb/unit) and 3.6 kg CP (3–3 Ib/unit). It was concluded that ammonia should be applied to grassland before April and, preferably, during March, for maximum yields of DM and CP.     

THE USE OF THE FORAGE HARVESTER IN THE IMPROVEMENT OF ROUGH GRAZING

Considerable improvement has been achieved in rough grazings by fairly frequent close mowing with the forage harvester or flail mower, particularly when combined with manuring and surface seeding.
The implement has proved capable of tackling very tough vegetation and converting it into grazing swards of fair value and good botanical composition. Undesirable species have been largely eliminated by treatment over two growing seasons.
The method is believed to compare favourably in cost with sward renovation by cultivation or by herbicides.     

THE ROLE OF GREEN SOILING IN THE ECONOMY OF THE DAIRY FARM

With modern machinery and modem techniques of grass production, mechanical-or zero-grazing offers a means of utilizing the crop to perfection. Whether this results in enhanced profits depends largely upon the farm and the specific circumstances. It may, it may not. What is evident is that the health of the cows is not affected by an unnatural manner of summer feeding; the sward, per se, may be improved by the regular and uniform defoliation; and under conditions of intensive production and the vital need to use profitably every blade of grass, as for instance on small, highly-rented farms, the practice of zero-grazing merits the most careful consideration. It cannot lightly be dismissed as merely a new fad.     

THE USE OF THE IN VITRO TECHNIQUE IN THE DETERMINATION OF THE DIGESTIBILITY OF GRASS/LEGUME MIXTURES

The in vitro dry-matter digestibility was determined of two samples of Digitaria decumbens , one sample of Medicago sativa , and one sample of Trifolium repens and nine mixtures prepared from these samples.
When the results were compared with in vivo digestibilities the standard errors of the regressions for the three combinations of legume, grass and legume/grass mixtures were ±0.6, ±0.6 and ±1.5 percentage units, respectively.
It is considered that in vivo digestibility of mixtures of grasses and legumes can be estimated by the in vitro technique, provided that suitable grass and legume standards are included.     

光周期对马铃薯块茎形成的影响及对激素的调节

马铃薯出苗后接受１个月的每日８小时短日照处理并与当时自然光照长度进行比较，研究光照长度对块茎形成及内源激素②的影响，探讨块茎形成与激素水平的关系。结果表明：短日照处理使块茎形成显著提早，但使结薯数减少，植株茎叶生长受抑，块茎淀粉含量降低；短日照处理使叶片中ＡＢＡ含量提早增高，ＧＡ３含量提早减少，ＧＡ３与ＡＢＡ的比值提早显著降低．     

THE EFFECT OF TEMPERATURE IN THE MASS ON THE CHEMICAL COMPOSITION OF SILAGE

The effect of temperature on silage quality was investigated in a series of trials over a period of three years.
The results indicated that when conditions in the silage were favourable for the formation of lactic acid, either through treatment or because of the herbage itself, low temperatures in the mass had no adverse effect on silage quality.
Some results suggest that, with chopped or lacerated silage, low maximum temperatures are associated with better quality silage. The results, however, were not entirely consistent.
There appeared to be little or no advantage in allowing unchopped silage to heat to 100°F.     

菜用大豆荚皮性状与产量形成的关系

利用菜用大豆的四个杂交组合,对其荚皮性状即荚皮的长、宽、表面积以及荚皮的内膜层、革质层等性状进行试验观察,并分别与子粒、产量进行相关分析.荚皮的长、宽、表面积、荚皮内膜层、荚皮革质层与产量有极显著正相关,荚皮表面积与产量的相关系数达0.6795**,内膜层鲜重与产量的相关系数和通径分析均达到0.8433**.革质层与子粒的相关性较大,百荚革质层的鲜重、风干重与百粒重的相关系数达0.6681**、0.6112**,荚皮厚与子粒鲜、干重及产量均呈极小不显著的正负相关(-0.0706～0.2810).在育种工作中应重视荚皮的表面积、内膜层和革质层等对产量和产品质量的影响.