追氮对夏玉米淀粉含量及其糊化特性的影响

以郑单958为材料,研究玉米随追氮量增加玉米籽粒淀粉含量、淀粉相关酶活性及其淀粉糊化特性的影响,研究结果表明玉米籽粒淀粉及直链淀粉含量随追氮量的增加先升高后略有下降;腺苷二磷酸葡萄糖焦磷酸化酶(ADPG-PPase)、尿苷二磷酸葡萄糖焦磷酸化酶(UDPG-PPase)及束缚态淀粉合成酶(GBSS)的活性随追氮量的增加先升高后降低。可溶性淀粉合成酶(SSS)的活性随追氮量的增加先降低后升高;随追氮量的增加淀粉的峰值黏度、低谷黏度、最终黏度及崩解值先升高后降低,峰值时间以及糊化温度先降低后升高。     

Interrelationship of nitrogen nutrition with maize (Zea mays) grain yield,nitrogen use efficiency and grain quality

Eight maize (Zea mays L) hybrids were grown under five N levels with or without the nitrification inhibitor, nitrapyrin (2-chloro-[6-trichloro-methyl] pyridine), to evaluate N interactions relative to yield performance, N use efficiency, grain protein concentration, and kernel texture. Results indicate that maize hybrids can be grouped into three categories based on grain yield: (1) low N-responsive types which reach their maximum yield with 134 kg ha^?1 of applied N; (2) intermediate types that respond to moderate N levels (134 to 201 kg N ha^?1); and (3) high N-responsive types that respond to higher levels of N (201 kg N ha^?1). High N-responsive types, in general, increased yield with nitrapyrin treatment at all levels of N. Crop N utilisation efficiency for high N-responsive hybrids decreased, but was static for low N-responsive hybrids as N fertiliser increased. In general, as the grain yield of a hybrid increased in response to N, the concentration of protein in the kernel increased; although grain yields and protein concentration are negatively correlated among hybrids. Increased kernel translucence, an indicator of kernel hardness induced by N fertiliser, correlated highly positive with zein proteins. Isoelectric focusing analysis showed that increases in zein were primarily due to a quantitative increase in α- and γ-zein polypeptides. This study indicates that hybrids are different in their N requirements for maximum yield. Low N conditions not only restrict grain yield but also affect kernel textural quality.     

不同基因型玉米籽粒发育过程中糖代谢相关酶活性的比较

对高淀粉玉米与低淀粉玉米籽粒发育过程中蔗糖代谢和淀粉合成相关酶活性的变化动态进行了比较研究。结果表明,费玉3号籽粒支链淀粉、直链淀粉及总淀粉积累速率高于豫玉22;费玉3号籽粒支链淀粉、直链淀粉及总淀粉含量大于豫玉22;豫玉22的高峰黏度、低谷黏度、最终黏度及胶凝值均显著高于费玉3号,其崩解值和糊化温度低于费玉3号;豫玉22的可溶性糖含量高于费玉3号;费玉3号的腺苷二磷酸葡萄糖焦磷酸化酶(ADPG-PPase)活性、尿苷二磷酸葡萄糖焦磷酸化酶(UDPG-Ppase)活性、可溶性淀粉合成酶(SSS)活性、束缚态淀粉合成酶(GBSS)活性高于豫玉22。     

The yield and quality of fresh and ensiled plant material from intercropped maize (Zea mays) and beans (Phaseolus vulgaris)

An investigation was carried out in the UK to determine whether intercropping with Phaseolus vulgaris beans increases the yield and nutritional quality of maize forage. Fresh and dry yields arising from different sowing dates and different densities of the two species were evaluated, with total nitrogen concentration (TNC) of the plants, and crude protein concentration (CPC), dry matter, metabolizable energy (ME), pH and starch, lactic acid and ash contents of ensiled material. Highest biomass yields of intercrops were obtained when the two species were planted simultaneously. There was a higher TNC in intercropped maize plants than in maize plants grown without beans (P < 0.05). Biomass yields were not significantly higher with a higher density of maize in the intercrop than with a lower density, nor were they higher with monocrop maize than with intercropping. However, the biomass had higher CPC at 75 000 maize plus 50 000 beans ha^?1 and 50 000 maize plus 50 000 beans ha^?1 than monocrop maize. Other nutritional characteristics of the silage made from the intercrop treatments were not significantly different from those of the silage made from monocrop maize. As the silage from intercrops of 75 000 maize plus 50 000 beans ha^?1 and 50 000 maize plus 50 000 beans ha^?1 gave more CP per land area than monocrop silage, and gave biomass yields that were not significantly different from monocrop maize, it was concluded that such intercropping is suitable for producing high‐quality silage under similar agro‐climatic conditions. Copyright © 2007 Society of Chemical Industry     

郑单958与先玉335玉米籽粒淀粉粒分布的比较

以郑单958及先玉335玉米为材料,利用激光衍射粒度分析仪及扫描电镜,分析玉米籽粒淀粉粒形态及分布特征。结果表明,两品种籽粒淀粉粒体积分布均为三峰曲线,峰值分布均在1.919,5.355及18.00μm;两品种籽粒淀粉粒表面积分布为三峰曲线,其峰值分别为1.322(1.097),5.355及16.40μm;郑单958、先玉335籽粒淀粉粒数目分布为双峰曲线,其峰值分别为0.627(0.688)及4.878(4.444)μm。两玉米品种>15μm所占体积最大,而<2μm淀粉粒所占体积最小; <2μm淀粉粒所占表面积及数目均最高,>15μm淀粉粒所占数目最小。郑单958及先玉335淀粉粒分布范围分别为0.375-39.78,0.375-30.07μm;淀粉粒体积及表面积均值均是先玉335>郑单958,而淀粉粒数目均值则是郑单958>先玉335。淀粉粒含量与2-15μm范围的淀粉粒体积和数目呈显著正相关,和其他淀粉粒分布特性相关性不显著。郑单958玉米籽粒淀粉粒呈圆形或椭圆形,大小不均匀,淀粉粒排布致密,脂体含量丰富;先玉335大多呈圆形,大小均匀,淀粉粒排布分布较郑单958稀疏,脂体含量少于郑单958。     

不同种植密度对夏玉米胚乳细胞淀粉粒分布及形态的影响

以郑单958为材料,通过不同种植密度,利用激光衍射粒度分析仪、扫描电镜及透射电镜,分析不同种植密度夏玉米胚乳籽粒淀粉粒粒度分布特征.结果表明,不同种植密度玉米籽粒淀粉粒的粒径下限一致(0.38 μm),上限D1＞D2＞D3;体积、表面积及数目均值:D2＞D3＞D1.从淀粉粒的扫描图可以看出不同处理淀粉粒形态及胚乳细胞内...     

Timing and rate of nitrogen application influence grain quality and yield in maize planted at high and low densities

BACKGROUND: Efficient use of nitrogen (N) is considered one of the most important inputs needed for increasing grain quality and crop productivity. Hypothesis was that grain quality and yield of maize (Zea mays L.) in north‐west Pakistan are enhanced by increasing the rate of N, and that response to applied N is greater with an increase in the number of N split applications at high plant density compared to low density. RESULTS: Field experiments were carried out on maize (cv. Azam) in summer 2002 and 2003 consisting of two planting densities and three N rates as main plots, and six split N applications as sub‐plots. Year 1 had higher shelling percentage and stover yield (SY). Harvest index (HI) decreased but SY increased with increase in plant density. Increase in N rate and number of split N applications increased grain weight and protein content, HI and SY. CONCLUSION: The highest N rate in four to five split applications increased maize grain quality and yield at both densities. Maize response to the interactive effect of year × plant density, year × N rate, and year × N timing suggests zonal specific effective N management practices for sustainable maize production in different agro‐ecological zones. Copyright © 2009 Society of Chemical Industry