叶面喷施氧化型谷胱甘肽对设施草莓光合作用、产量和品质的影响

为了缓解京郊冬春季雾霾寡照对设施草莓产量和品质的影响,以‘红颜’草莓为试验材料,在基质栽培条件下,研究了在草莓生长的不同时期喷施不同浓度氧化型谷胱甘肽(GSSG)对设施草莓光合速率、产量和品质的影响。结果表明,喷施谷胱甘肽有氧化型(GSSG)显著提升了草莓的产量。GSSG浓度与前两茬果和总产量符合线性-平台的模型,当GSSG浓度为180~300 mg/L时,草莓产量达到最大,继续增加GSSG浓度产量不再增加。草莓产量的提升主要是由于喷施GSSG后草莓结果数显著增加,GSSG浓度为150~300 mg/L时,头茬果和二茬果的果数均显著增加;GSSG浓度大于150 mg/L时,草莓叶面积、叶片光合速率随着GSSG浓度的增加而增加,草莓的产量与叶面积和光合速率呈显著的正相关关系。喷施GSSG浓度为300 mg/L时对草莓的糖度有一定提升。综合考虑,在设施草莓生产中,在草莓生长的不同时期喷施180~300 mg/L GSSG,有利于减缓冬春季雾霾寡照天气对设施草莓生长的不利影响,从而提高草莓的产量和品质。

长三角地区蔬菜生产的活性氮损失和温室气体排放估算

基于相关统计数据,本文采用生命周期评价(LCA)方法,研究了长三角地区三省一市蔬菜生产的活性氮损失和温室气体排放。结果表明:长三角地区蔬菜生产的活性氮损失和温室气体排放潜值较高,2012—2016年平均分别为103 kg N·hm^-2和5930 kg CO2-eq·hm^-2;不同年份间活性氮损失和温室气体排放差异显著,2015年活性氮损失和温室气体排放潜值最低,分别为95 kg N·hm^-2和5618 kg CO2-eq·hm^-2,其活性氮损失和温室气体排放潜值分别较其他年份低6.5%~12.3%和3.5%~9.0%;5 a平均活性氮损失和温室气体排放潜值露地蔬菜分别为106 kg N·hm^-2和5157 kg CO2-eq·hm^-2;设施蔬菜分别为93 kg N·hm^-2和8760 kg CO2-eq·hm^-2;与该区其他省市蔬菜生产相比,浙江5 a平均活性氮损失低2.8%~13.7%,安徽温室气体排放潜值低1.4%~10.7%。针对蔬菜生产高氮肥投入、活性氮损失以及温室气体排放问题,在田间管理时可采取控制氮肥用量、优化施用氮肥、合理使用增效氮肥等措施。

不同有机物料对设施黄瓜生长及土壤性状的影响

为了减少设施菜田中由于超量施用有机肥导致的N、P累积,通过选取泥炭、腐植酸、菌渣、生物炭4种有机物料及其配施对传统鸡粪进行等C替代,开展了两茬田间试验,研究了有机物料等C替代鸡粪对土壤理化性质和黄瓜产量、品质的影响。连续两茬的试验结果表明,有机物料等C替代鸡粪对黄瓜产量无显著影响;但同鸡粪处理相比,泥炭、腐植酸和生物炭3种有机物料配施可显著提高黄瓜果实中维生素C的含量;除单施生物炭外,施用不同有机物料表层土壤(0~20cm)的pH值均显著高于施用鸡粪的处理,同时有机物料处理较鸡粪处理降低了表层土壤有效P含量51.6%~62.9%,提高了表层土壤C/N,其中,腐植酸处理土壤有效P的降低幅度最大,且其表层土壤C/N与鸡粪相比显著提高了92.2%,腐植酸处理土壤(0~60cm)的C储量也最大;各有机物料处理N盈余量均小于鸡粪处理,其中生物炭处理的养分盈余量最小,与鸡粪相比减少了73.1%,各有机物料处理的P盈余量与鸡粪处理相比显著降低了65.3%~92.3%,P削减效果腐植酸>泥炭+腐植酸>泥炭+腐植酸+生物炭>生物炭>泥炭>泥炭+菌渣>菌渣。因此,有机物料等C替代鸡粪后,在保证黄瓜产量的同时可以提升黄瓜果实营养品质,大幅度削减土壤中N、P盈余,其中,腐植酸对提高土壤有机质以及P盈余削减效果较好,泥炭+腐植酸+菌渣配施对改善黄瓜品质的效果较好。

Effects of long-term green manure application on the content and structure of dissolved organic matter in red paddy soil

Dissolved organic matter(DOM) plays important roles in soil biogeochemistry activity and nutrients transportation in soils, but studies regarding the long-term effects of green manures on the content and structure of DOM in red paddy soil have not been reported yet. A long-term green manure experiment established in 1982 was utilized to test the DOM contents in different treatments, and the spectral characteristics of DOM were investigated by using ultraviolet-visible(UV-Vis) spectrometry and Fourier transform infrared(FTIR) spectrometry. The experiment included four cropping systems: ricerice-milk vetch(RRV), rice-rice-rape(RRP), rice-rice-ryegrass(RRG) and rice-rice-winter fallow(RRF), among them, milk vetch, rape, and ryegrass are popular winter green manure species in southern China. The results showed that the content of dissolved organic carbon(DOC), which is widely used to estimate the concentration of DOM, was significantly promoted after the incorporation of green manures compared with the other sampling stages. The contents of aromatic groups and the degree of humification of DOM increased in RRV and RRP, suggesting more complex compositions of the soil DOM after long-term application of milk vetch and rape. The contents of phenol, alcohol and carboxylic acid group at the mature stage of early rice were significantly higher than those at the stage of after green manures turned over, especially for the RRV treatment. The absorption ratio of FTIR indicated that winter plantation of rape increased the aromatic-C/aliphatic-C ratio, and ryegrass increased the aromatic-C/carboxyl-C ratio. In conclusion, long-term planting of milk vetch and rape as green manures increased the degree of aromaticity, humification and average molecular weight of DOM, and made the DOM more stable in red paddy soil.

Characterization of Quantitative Trait Loci for Grain Minerals in Hexaploid Wheat (Triticum aestivum L.)

Wheat is an important source of essential minerals for human body. Breeding wheat with high grain mineral concentration thus benefits human health. The objective of present study was to identify quantitative trait loci （QTLs） controlling grain mineral concentration and to evaluate the relation between nitrogen （N） and other essential minerals in winter wheat. Wheat grains were harvested from field experiment which conducted in China and analyzed for this purpose. Forty-three QTLs controlling grain mineral concentration and nitrogen-related traits were detected by using a double haploid （DH） population derived from winter wheat varieties Hanxuan 10 and Lumai 14. Chromosomes 4D and 5A might be very important in controlling mineral status in wheat grains. Significant positive correlations were found between grain nitrogen concentration （GNC） and nutrients Fe, Mn, Cu, Mg concentrations （FeGC, MnGC, CuGC, MgGC）. Flag leafN concentration at anthesis （FLNC） significantly and positively correlated with GNC, FeGC, MnGC, and CuGC. The study extended our knowledge on minerals in wheat grains and suggested which interactions between minerals should be considered in future breeding program.

Responses of Aerobic Rice (Oryza sativa L.) to Iron Deficiency

Aerobic rice has the advantage of saving water. Most published work has focused on improving its yield, while few reported on its micronutrient status. In fact, Fe deficiency is a common nutritional problem in the production of aerobic rice. Short- term hydroponic culture experiments were conducted to study the response of aerobic rice to Fe deficiency and the effect of root exudates from Fe-deficient wheat on its Fe uptake ability. The results indicate that the amount of phytosiderophores （PS） released from aerobic rice did not increase under Fe deficient conditions. The Fe（III） reducing capacity of Fe-deficient aerobic rice did not increase and the solution pH did not decrease significantly. What＇s more, no obvious swelling was observed in the root tips. Aerobic rice did not show special responses to improve their Fe nutrition under Fe deficiency as both strategy I and II plants though they were very sensitive to Fe deficiency. This may be a reason which causes Fe deficiency problem in aerobic rice. However, root exudates from Fe-deficient wheat （PSw） could improve its Fe nutrition in the presence of insoluble Fe（OH）3. This suggests that aerobic rice could utilize Fe activated by PSw.

设施基质条件下不同茬口樱桃番茄的养分吸收及分配规律研究

以樱桃番茄为供试材料,通过设施基质栽培试验,研究了不同茬口樱桃番茄的养分吸收规律和分配特点,旨在为樱桃番茄的科学施肥提供依据。结果表明:形成1000 kg果实樱桃番茄植株的N、P、K、Ca、Mg吸收量分别是4.31～4.79 kg、0.68～0.78 kg、5.60～6.43 kg、0.68～0.99 kg、0.31～0.48 kg,两茬樱桃番茄养分吸收比例N∶P∶K∶Ca∶Mg分别是1∶0.16∶1.30∶0.23∶0.11和1∶0.16∶1.34∶0.14∶0.06,在结果期,有40%～50%的N、P、K分配在果实中,而钙和镁在果实中的分配比例只有10%左右。Fe、Mn、B、Zn、Cu的吸收量分别是14～18 mg株-1、10～14 mg株-1、6.3～7.5 mg株-1、5.3～6.6 mg株-1、0.6～0.7 mg株-1。樱桃番茄的干物质累积以及养分吸收量从开花期以后迅速增加,N、P、K在开花期的累积量占整个生育期的比例是7.6%～14.4%,Ca、Mg在开花期的累积量能达到20%左右,所以在开花期要注重钙镁的补充。盛果期各养分的累积量占比最大,是养分大量吸收累积的关键时期,这一时期需要提供充足的营养保证果实的建成。