烤烟成熟期控水对烟叶碳氮代谢关键酶活的影响?

成熟期是烤烟需水次临界期。为明确烤烟成熟期土壤水分对烟叶碳氮代谢的影响,试验在烤烟成熟期进行土壤控水,研究烟叶碳氮代谢主要关键酶活性的变化。结果表明：土壤水分亏缺（50%~60%田间持水量）致烟叶叶绿素含量降低,土壤水分充足（80%~85%田间持水量）烟叶绿素含量高,烟叶成熟缓慢,且复水能缓解干旱胁迫导致的烟叶早衰;烟叶成熟期,湿润土壤（70%~85%田间持水量）烟叶硝酸还原酶、转化酶和淀粉酶活性较高,土壤干旱使烟叶碳氮代谢关键酶活性减弱,但复水在一定程度上能恢复淀粉酶活性。     

烤烟成熟期控水对烟叶主要碳氮化合物含量的影响

成熟期是烤烟需水次临界期。为明确烤烟成熟期土壤水分对烟叶主要碳氮化合物的影响,试验在烤烟成熟期进行土壤控水,研究烟叶总糖、还原糖、淀粉、总氮和烟碱等的变化。结果表明：土壤含水率70%~85%,烤烟生长后期（移栽后约83天）烟叶总糖、还原糖和淀粉含量较高;干旱胁迫降低碳代谢,而干旱后复水碳代谢增强。70%~85%土壤含水率,烤烟总氮和烟碱水平较低;干旱胁迫促进氮代谢,总氮和烟碱含量较高;干旱胁迫后复水,烟叶总氮和烟碱含量处于中等水平。烤烟成熟期,土壤水分过高或过低,均不利于协调烟叶碳氮代谢平衡。     

再生稻栽培技术的研究进展

根据已报到的研究材料,综述了中国南方稻区再生稻的研究进展。所有的水稻品种均可获得一定的再生稻产量,常规品种的再生稻产量明显低于杂交水稻的再生稻产量,而三系杂交水稻的再生稻产量又较两系杂交稻的再生稻产量低;留桩高度各地因组合不同和生态条件不同而有一定的差异,一般为10~40 cm;各节间腋芽在温度、光照和水分适宜的条件下均能较好的萌发,施用赤霉素和细胞分裂素均能有效促进腋芽的萌发,并能提高再生芽的成活率;再生稻腋芽萌发及成活的最适温度为24.5~27.0℃,相对湿度为81%~85%,‘汕优63’再生稻结实率≥70%的临界低温指标是：连续5日平均气温≥21℃;头季稻齐穗期剑叶SPAD值、叶片含氮量和群体单位面积的总颖花量3个因子可以用来预测再生稻高产的促芽肥经济施用量;超级杂交稻也可获得较好的再生稻产量。再生稻的栽培技术还可进一步的研究。     

油棕园间套种菠萝对土壤养分及酶活性的影响

为了探索幼龄油棕园间套种菠萝对土壤养分以及酶活性的影响,采用大田试验,在油棕与不同品种菠萝间套种种植模式下比较分析油棕园土壤养分及土壤酶活性大小。结果表明：间套种菠萝能够降低土壤pH值,有机质含量间套种处理与对照差异不明显,菠萝收获期较生长期有机质含量提高。土壤碱解氮、有效磷含量间套种处理要高于对照,土壤速效钾生长期间套种处理高于对照,成熟期处理与对照间差异不显著。间套种处理整体上降低土壤脲酶和酸性磷酸酶的活性,但却提高了过氧化氢酶的活性。     

桃褐腐病菌激活蛋白对草莓幼苗防御酶酶活性的影响

激活蛋白是从多种病原真菌中分离出的一种蛋白激发子,为了解桃褐腐病菌激活蛋白对植物防御酶的诱导作用,本实验通过沸水浴、离心等方法,从桃褐腐病菌（Monilinia fructicola）菌丝体中分离出激活蛋白的粗提物,并喷雾到草莓幼苗的叶片上,测定了部分防御酶和病程相关蛋白的活性变化。结果表明：经桃褐腐病菌激活蛋白处理后,0-18h内草莓叶片的苯丙氨酸解氨酶(PAL)活性呈曲线增高的趋势,18h达到最高值,最高值比对照增加40.7%; 0-6h内草莓叶片过氧化物酶(POD) 和多酚氧化酶（PPO）活性均呈急剧增高的趋势,6h达到最高值,其中POD活性比对照增加126.2%,PPO活性比对照增加62.9%。经激活蛋白处理后草莓叶片的β-1,3-葡聚糖酶、几丁质酶活性也有增高的趋势。     

Cotton Chemical Topping by Applying DPC in Different Cotton-Growing Regions

[Objective] The objective of this study was to investigate the stability and universality of cotton chemical topping by applying mepiquat chloride (1,1-dimethyl-piperidinium chloride, DPC) in different cotton-growing regions. [Method] Field experiments were conducted in 2018 at 10 locations in the Yellow River basin (Hejian and Handan, Hebei province; Dezhou and Wudi, Shandong province), the Yangtze River basin (Dafeng, Jiangsu province; Huanggang, Hubei province), and Xinjiang area (Shihezi location I and loacation II, northern Xinjiang and Luntai and Shaya, southern Xinjiang). Local cultivars/lines were used, and the experiments were performed using a randomized complete block design with three or four replicates. Accompanied with typical DPC multi-application in each location, chemical topping was conducted at 10 days before manual topping (T1) or at the same time with manual topping (T2) by applying four dosages of DPC (0, 90, 180, 270 g·hm^－2), manual topping was used as the first control and non-topping as the second control. [Result] The time of chemical topping significantly affected cotton plant height (except for the results in Handan, Dezhou and Wudi) and the number of fruit branches (except for the results in Dafeng and Huanggang). It was observed that earlier chemical topping would result in lower cotton plant height and a fewer fruit branches. In Hejian and Shihezi location I, the average plant height across DPC chemical topping at T1 stage was not only lower than that of T2 stage but also 3.3 cm and 4.6 cm lower than that of manual topping, respectively. In most locations, chemical topping at T1 stage increased around two fruit branches per plant compared with manual topping, while in T2 stage the increased fruit branches per plant ranged from 2.3 to 7.7. Also, we found that a higher dosage of DPC resulted in shorter plant height (except for that in Huanggang). In some locations, plant heights of chemical topping with 180 g·hm^－2 or 270 g·hm^－2 DPC were even shorter than that of manual topping. The number of fruit branches per plant of 0 g·hm^－2 DPC increased by 2.4-8.3 compared with manual topping. However, chemical topping with 90-270 g·hm^－2 DPC significantly reduced the number of fruit branches compared with 0 g·hm^－2 DPC. There were no significant differences in the number of fruit branches among three DPC dosages (90, 180, and 270 g·hm^－2). In Handan, seed cotton yield of chemical topping at T2 stage was significantly lower than that of manual topping due to the decreased boll number, which is possibly associated with the high temperature and drought weather after chemical topping. While at other locations, most treatments of chemical topping by using DPC did not produce significant effects on yield. In addition, chemical topping by using DPC did not delay cotton maturity, characterized by their similar boll-opening rate and the first harvest rate to those of manual topping before spraying harvest aids. [Conclusion] Cotton chemical topping with DPC is more stable and universal across different cotton-growing regions. We suggest that 90-180 g·hm^－2 DPC could be used at the same time with manual topping for cotton chemical topping.     

具有中国大豆遗传背景的7S与11S多亚基缺失型大豆新品系的创制

利用我国高油大豆品种东农47与日本引进多亚基缺失型育种材料日B,采用回交、三交的育种方法,综合系谱选择,通过SDS-PAGE技术分析亚基组成,在BC₁、BC₃及三交种F₈群体内,选育到(α+11S groupⅡa)-缺失型、(α′+11S groupⅡa)-缺失型、[(α′+α)+11S groupⅡa、Ⅱb]-缺失型、[(α′+α)+11S groupⅡa]-缺失型、[(α′+α)+11S groupⅡb+X₁X₂]-缺失型、[(α′+α)+11S groupⅡb]-缺失型和(α′+11S groupⅠ、Ⅱa)-缺失型共7种具有中国大豆遗传背景的7S球蛋白α′、α亚基与11S球蛋白groupⅠ(A_1aB_1b,A₂B_1a,A_1bB₂)、groupⅡa(A₄A₅B₃)和groupⅡb(A₃B₄)不同亚基缺失组合新种质。测定优良品系的综合农艺性状及氨基酸组成、含量,结果表明,与对照相比,各种缺失突变体的各种氨基酸组分含量普遍提高,蛋白总量普遍高于轮回亲本,精氨酸含量特别是游离精氨酸的含量大幅提高。其中亚基组成为(α+11S groupⅡa)-缺失型品系G2-2-3的17种氨基酸含量、氨基酸总量、蛋氨酸含量均显著高于轮回亲本东农47,特别是游离精氨酸含量高出7.27mg/g。以上结果表明,7S与11S多亚基缺失型优良品系在有效去除致敏蛋白的同时,可以提高大豆蛋白氨基酸含量, 改善大豆蛋白氨基酸组分配比。各种致敏蛋白缺失型大豆优良新品系的获得,大大丰富了我国蛋白质组分改良育种的种质基础。     

不同栽培模式下水稻各生育期光合生理指标的比较研究

为明确膜下滴灌与常规水作栽培的光合生理差异。通过对膜下滴灌和淹灌2种栽培模式下,4个水稻品系(T-04、T-43、T-66、T-69)在分蘖、孕穗、抽穗、乳熟、蜡熟期倒一叶的光合色素含量、光合-叶绿素荧光参数、抗氧化酶活性以及渗透调节物质含量等光合生理指标的测定分析。结果表明:滴灌模式下,4个参试材料在5个关键生育期的蒸腾速率(Tr)、气孔导度(Gs)、光合速率(Pn)均低于淹灌,胞间CO_2浓度(Ci)总体上略低于淹灌,大部分时期差异不显著(P0.05);叶绿素荧光参数、光系统Ⅱ有效量子产量(ΦPSⅡ)、最大荧光(Fm)、暗适应光系统Ⅱ最大量子产量(Fv/Fm)总体上低于淹灌,大部分时期差异不显著,最小荧光(Fo)高于淹灌,荧光淬灭系数(q P、NPQ)在2种栽培模式下差异不大,叶绿素含量、类胡萝卜素含量、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性总体上低于淹灌,超氧化物歧化酶(SOD)活性在2种栽培模式下差异不显著,丙二醛(MDA)、脯氨酸(Pro)含量总体上高于淹灌,可溶性蛋白(SP)含量总体上低于淹灌,可溶性糖(SS)含量差异不显著。水稻膜下滴灌栽培整个生育期均无水层覆盖,可能受到水分胁迫,导致其整个生育期大部分光合生理指标均低于淹灌。     

浅圆仓充氮气调技术实仓应用探究

通过对浅圆仓采用不同方法进行充氮试验,探索最佳的浅圆仓充氮气调储粮工艺。试验结果表明,采用上充下排方式,先以设备允许的最大流量(流量165m~3/h,浓度95%)充入氮气,当仓内氮气浓度接近95%时,再逐步提高设备氮气浓度至99%(流量90m~3/h),此工艺相较其他方法充氮速率略高,能耗相对略低,仓内氮气分布均匀。     

农杆菌介导高粱遗传转化的相关因素优化

为建立一个稳定的高粱遗传转化体系,以高粱RHMC品种为试验材料,采用内含有P ^CAMBIA3301质粒载体的根癌农杆菌EHA105介导的方法研究了高粱遗传转化的相关因素。结果表明,外植体预培养2d,GUS表达效果最好;在侵染液和共培养基中加入200μmol/L乙酰丁香酮时,GUS表达效果最好;侵染液浓度OD₆₀₀值的适宜范围为0.8~1.0;农杆菌侵染愈伤组织的适宜时间为5~10min;共培养的适宜时间为2d。初步建立了一套高粱遗传转化体系,为今后高粱转化提供一些参考。