中国玉米种子质量:十年变迁和未来展望

种子是农业科技的载体,种子质量代表着国家农业科技水平,决定了品种推广范围、播种方式及种子市场竞争力。质量调研作为种子质量保障的一项基础性工作,对推动现代种业高质量发展发挥着重要作用。从包衣包装、4项基本指标测定、种子活力测定、合格率、交流问卷等方面回顾了中国玉米主产区市售品种样品种子质量十年变迁概况,并从种子质量标准认证建设、种企高质量种子生产能力提升、种子质量科普培训及市场监管等方面对玉米种子质量有效控制、保障用种安全提出了一些建设性意见,为推进新时代中国现代玉米产业高质量发展提供参考。

盐碱地棉花花生间作种植模式对产量和效益的影响

为优化硫酸盐盐碱地棉花花生种植模式和提高单位土地面积综合经济效益,本研究以‘鲁棉研37号’和‘花育36号’为供试材料,在高唐硫酸盐盐碱地条件下,通过两年大田试验分析了棉花花生不同间作种植模式下作物产量、单位面积的土地当量比、种植成本和效益。结果表明,在试验点的气候条件下,棉花花生不同种植模式中两种作物产量存在年际间差异;棉花花生2:4和4:8间作种植模式的土地当量比、总效益、总成本和净效益均较高,其中4:8种植模式的最高。棉花花生4:8大小幅间作种植,年际间换带轮作,可作为当地棉花花生复合种植的最优配置。

适合糖尿病患者食用的藕粉馒头研发

利用一定比例的藕粉和小麦粉混合制作馒头,并进行比容和感官指标分析。通过单因素试验和正交试验确定了藕粉馒头的最佳工艺条件为藕粉添加量30%,水添加量55%,醒发时间15 min,按照此工艺制作的馒头香味纯正、松软可口,并对此进行血糖生成指数测定,结果为61.6,相对于普通馒头的88.7左右,降低了30.6%,属于中等血糖生成指数(GI)食品,可以作为特殊人群的主食适量食用,具有控制血糖、减轻体重的作用。

土壤和叶面施锌对小麦农艺性状、籽粒产量和对锌、铁及硒微量元素浓度的影响

锌(Zn)是动植物和人体必需的微量元素,能预防肺炎等疾病和提高人体免疫功能。小麦作为中国主要粮食作物,为满足人体对锌的营养需求,提高小麦籽粒锌含量十分必要。为给优质富锌小麦生产提供理论依据和技术支撑,通过在田间条件下进行土壤和叶面施锌试验,研究其对小麦农艺性状和籽粒产量的影响,尤其是对籽粒锌浓度的生物强化效果,以及对籽粒中其他2种有益微量元素(铁和硒)的影响规律。结果表明:土施锌肥使小麦穗数从447.0万穗/hm^(2)增加到511.5万穗/hm^(2),增幅14.4%。土壤和叶面施Zn使得小麦籽粒产量从5419.5~6250.5 kg/hm^(2)增加到6372.0~6811.5 kg/hm^(2),增幅5.2%~17.6%,对籽粒铁和硒浓度均无显著影响,有效提升籽粒Zn浓度,从34.0~39.6 mg/kg提高到44.6~46.6 mg/kg,增幅17.7%~32.9%,达到世界卫生组织等机构和科学家所推荐的生物强化目标值(40~50 mg/kg)。因此,土壤和叶面施Zn提高小麦产量的同时,可以提升籽粒锌营养品质,是实现小麦提质增效的有效途径,建议大面积推广应用。

不同施肥措施对盐渍土理化性状和玉米产量的影响

田间试验分别于轻、中度盐渍土条件下开展,共设置6个处理,分别为农民习惯施肥(T1,尿素分次施用,N 250 kg/hm^(2))、包膜增效尿素一次性基施(T2,180 kg/hm^(2))、包膜增效尿素配施微生物肥(T3,180 kg/hm^(2))、包膜增效尿素配施有机肥(T4,轻、中度盐碱土的施氮量分别为162 kg/hm^(2)和144 kg/hm^(2))、包膜增效尿素配施秸秆腐熟剂(T5,180 kg/hm^(2))、有机无机复合肥一次性基施(T6,162 kg/hm^(2)),研究不同施肥措施对盐渍土理化性状和玉米产量的影响。结果表明,在轻度盐渍土条件下,与T1相比,不同施肥处理对玉米产量、氮肥偏生产力(PFPN)、不同土层钠吸附比(SAR)和电导率(EC值)无显著影响,但会显著提高0~20 cm土层有机碳含量。在中度盐渍土条件下,不同施肥措施对玉米产量无显著影响,其中T4和T5处理产量表现最好;与T1相比,T4处理的PFPN显著提高16.6 kg/kg;不同施肥措施有降低0~20 cm土层SAR和EC值的趋势,其中T4处理表现最好。此外,T4处理可以显著增加0~20 cm土层有机碳含量。综合认为,在中度盐渍土条件下,包膜增效尿素减量配施有机肥对玉米产量提高和缓解土壤盐渍化有重要促进作用。

NO_(3)^(-)缓解小麦NH_(4)^(+)胁迫的生理机制研究

本实验研究了NO3-对单一NH4+胁迫下小麦(Triticum aestivum)根系生理特性的响应机制。结果表明:单一NH4+处理下,与对照相比,根系鲜重显著降低;吲哚乙酸(IAA)和茉莉酸含量显著降低,水杨酸含量显著升高;抗氧化酶活性显著降低,活性氧与丙二醛含量显著升高;氮代谢酶活性显著降低,谷氨酰胺含量显著增加。傅里叶转换红外光谱检测表明,纤维素、木质素等峰值增大,其含量也显著升高。非损伤微测结果表明,NH4+、H+外排速率以及IAA内流速率增加。NH4++NO3-处理能提高小麦根系IAA、茉莉酸等激素含量,降低水杨酸含量,提高抗氧化酶与氮代谢关键酶活性,降低NH4+、H+外排速率以及细胞壁结构性成分的含量,从而缓解NH4+抑制作用。综上所述,NH4++NO3-处理有效缓解了单一NH4+处理对小麦根系的抑制作用。

Maize grain concentrations and above-ground shoot acquisition of micronutrients as affected by intercropping with turnip, faba bean, chickpea, and soybean

Most research on micronutrients in maize has focused on maize grown as a monocrop. The aim of this study was to determine the effects of intercropping on the concentrations of micronutrients in maize grain and their acquisition via the shoot. We conducted field experiments to investigate the effects of intercropping with turnip (Brassica campestris L.), faba bean (Vicia faba L.), chickpea (Cicer arietinum L.), and soybean (Glycine max L.) on the iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn) concentrations in the grain and their acquisition via the above-ground shoots of maize (Zea mays L.). Compared with monocropped maize grain, the grain of maize intercropped with legumes showed lower concentrations of Fe, Mn, Cu, and Zn and lower values of their corresponding harvest indexes. The micronutrient concentrations and harvest indexes in grain of maize intercropped with turnip were the same as those in monocropped maize grain. Intercropping stimulated the above-ground maize shoot acquisition of Fe, Mn, Cu and Zn, when averaged over different phosphorus (P) application rates. To our knowledge, this is the first report on the effects of intercropping on micronutrient concentrations in maize grain and on micronutrients acquisition via maize shoots (straw+grain). The maize grain Fe and Cu concentrations, but not Mn and Zn concentrations, were negatively correlated with maize grain yields. The concentrations of Fe, Mn, Cu, and Zn in maize grain were positively correlated with their corresponding harvest indexes. The decreased Fe, Mn, Cu, and Zn concentrations in grain of maize intercropped with legumes were attributed to reduced translocation of Fe, Mn, Cu, and Zn from vegetative tissues to grains. This may also be related to the delayed senescence of maize plants intercropped with legumes. We conclude that turnip/maize intercropping is beneficial to obtain high maize grain yield without decreased concentrations of Fe, Mn, Cu, and Zn in the grain. Further research is required to clarify the mechanisms underlying the changes in micronutrient concentrations in grain of intercropped maize.