不同棱型大麦品种混种增产效果初探

为了探索不同棱型大麦品种混种的增产机理及效果,以保山市大面积推广的多棱品种保大麦14号、二棱品种82-1为材料,设5个处理,进行单种和混种比较试验,结果表明,混种能充分利用空间、利用光能,从而提高产量,产量比单种二棱矮秆品种增加139.5～719㎏/hm2,比单种多棱高秆品种增40.5～720㎏/hm2;产量构成因素中,有效穗与单种二棱品种(单种中有效穗最多)相近,穗实粒数比单种二棱矮秆品种增7.8～10.7粒,千粒重比单种多棱高秆品种增1.2～5.5g,同时,混种还能减轻倒伏;二棱品种82-1与多棱品种保大麦14号混种基本苗最佳比例为6:4(折合种子重量≈7:3)。     

油菜纸钵苗移栽机气动插入式取苗过程分析与试验

设计一种油菜纸钵苗移栽机气动插入式取苗装置,构建取苗过程的力学模型,通过取苗各阶段的关键参数优选试验,获得取苗装置最优参数组合。选择倒四棱台形纸钵,并设计一种双针插入式取苗末端执行器,根据取苗针间距要求确定取苗执行气缸型号为MHS4-20D。气动取苗过程分为取苗阶段、送苗阶段和脱苗阶段,各阶段力学分析与参数优选试验表明,取苗针与苗钵基质间摩擦力不小于3.67 N、苗钵脱落高度低于380mm时取苗装置可有效实施取苗功能。台架试验表明,当取苗针为直径4mm不锈钢、插入苗钵基质深度20mm、脱苗高度340mm时,取苗成功率达92%。田间试验结果表明,气动插入式取苗装置取苗效果满足钵苗移栽机技术要求。     

Why high grain yield can be achieved in single seedling machine-transplanted hybrid rice under dense planting conditions?

This study was conducted to identify the factors associated with high grain yield in single seedling machine-transplanted hybrid rice under dense planting conditions. Field experiments were done in Yong'an Town, Hunan Province, China in 2015 and 2016. Two hybrid rice cultivars were grown under single seedling machine transplanting (SMT) and conventional machine transplanting (CMT) at a high planting density in each year. Grain yield and yield attributes were compared between SMT and CMT. Averaged across cultivars and years, grain yield was 12% higher under SMT than under CMT. Plant height, basal stem width, and shoot and root dry weights were higher in seedlings for SMT than those for CMT. SMT had less maximum tiller number per m² and consequently less panicle number per m² than did CMT. Branch number per panicle, especially the secondary branch number per panicle, and spikelet number per cm of panicle length were more under SMT than under CMT, which resulted in more spikelet number per panicle under SMT than under CMT. SMT had higher or equal spikelet filling percentage than did CMT. The difference in grain weight between SMT and CMT was relatively small and inconsistent cross years. SMT had higher or equal total biomass and harvest index than did CMT. Dry weight per stem under SMT was heavier than that under CMT. Larger leaf area per stem was partly responsible for the heavier dry weight per stem under SMT than under CMT. Our study suggests that improvement in seedling quality, panicle size, and dry weight per stem are critical to the high grain yield in single seedling machine-transplanted hybrid rice under dense planting conditions.     

河滩地杨树扦插育苗技术

本文重点阐述了水保育苗基地在地下水位较高、盐碱含量较大的河滩等地杨树扦插育 苗的生产实践及育苗经验技术,以期为育苗工作者提供借鉴。     

甘蓝型油菜抗寒性鉴定方法的建立和种质资源筛选

为筛选可利用的抗寒种质资源,建立了甘蓝型油菜抗寒性鉴定方法：将3叶期到4叶期的幼苗经4℃预处理（低温锻炼）24h,然后分别做4种冷冻处理（-2℃1h、-2℃1h+-4℃1h、-2℃1h+-4℃1h +-6℃1h）,随后统计存活率,计算抗寒指数,评估抗寒性。通过该方法对来自国内外的226份油菜资源进行抗寒性评价,结果表明：4种冷冻处理下,供试材料的存活率差别明显,抗寒指数范围是0~52。从中筛选出6份强抗寒性的种质,抗寒指数大于33;根据不同生态区划分,冬性、半冬性和春性材料的平均抗寒指数分别为8.10、7.70和9.10,春性材料抗寒性最优,也说明鉴定方法具有准确性。     

磷肥对西藏青稞叶水势、光合生理及产量因素的影响

为探讨施磷量对西藏青稞叶水势、光合、产量等因素的影响,以西藏主栽春青稞品种喜马拉雅22号为试材,通过田间微区试验,设不施磷(CK)、低磷(P2O575kg·hm~(-2))、中磷(P2O5150kg·hm~(-2))和高磷(P2O5225kg·hm~(-2))处理,测定青稞开花后4d的旗叶水势(LWP)、光合和叶绿素荧光参数,以及成熟后千粒重和产量,并利用数字图像分析法精准提取籽粒表型性状。结果表明,与CK相比,施磷可明显降低青稞旗叶水势,显著提高旗叶和倒2叶叶绿素含量,但磷肥处理间叶绿素含量差异不显著;施磷条件下青稞旗叶净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)均高于CK(除高磷处理的Tr外),其中低磷条件下最大,而高磷条件下最低;胞间CO_2浓度(Ci)随施磷量增加呈下降-平稳-下降趋势。PSII的最大量子效率(Fv/Fm)、实际光量子产量(ΦPSⅡ)、光合电子传递的相对速率(ETR)、光化学淬灭(qP)值随施磷量的增加均呈先增后降趋势,并以中磷处理最大;非光化学淬灭(qN)在CK、低磷、中磷处理间差异较小,而高磷处理时显著下降。随着施磷量的增加,籽粒二维面积、直径、周长、长度、宽度均呈增大趋势,而粒圆度呈减小趋势。随施磷量的增加,小粒和较小粒占比逐渐下降,而中粒和大粒占比逐渐提高。低磷处理下青稞千粒重和籽粒产量分别较CK提高6.66%和17.53%,中磷处理分别提高17.20%和21.10%,高磷处理分别提高8.72%和16.16%,但磷肥利用效率(PUE)随施磷量增加呈逐渐降低趋势。综合来看,在本试验条件下,青稞适宜施磷量应控制在75～150kg·hm~(-2)以内。     

青稞类钙调素蛋白基因CML19的克隆、序列分析及原核表达

根据鉴定得到青稞类钙调素蛋白基因CML19的序列设计引物,以青稞叶片的cDNA为模板,扩增得到目的片段,对目的基因序列进行鉴定和分析,进一步构建该基因的原核表达载体pET28a-CML19,转入大肠杆菌BL21(DE3),利用IPTG诱导外源蛋白质表达并检测。结果表明,扩增得到CML19的CDS序列全长为447bp,编码的蛋白质含有148个氨基酸,分子质量为16.46ku,理论等电点(pI)为4.40,总平均亲水性(GRAVY)为-0.176,不稳定系数为49.59,存在典型的EF手结构域;系统进化分析表明,青稞CML19与山羊草具有较近的亲缘关系;原核表达蛋白结果显示,重组蛋白主要以包涵体形式存在于沉淀中。初步阐明青稞CML19基因的序列特征,为进一步制备抗体、探讨CML19基因的功能奠定基础。     

水稻立枯病抗性资源筛选

利用黑龙江省226份水稻种质资源进行苗期耐立枯病的鉴定,以轮枝镰刀菌为供试菌株,采用人工接种,筛选得到不同表现值的抗源材料。鉴定结果表明:鉴定筛选出高抗品种12份,分别为‘龙粳20号’‘东农429’‘富士光’‘龙稻5号’‘龙粳27号’‘垦稻18’‘黑粳2号’‘龙粳21号’‘朴洪根稻’‘石狩白毛’‘垦稻9’‘垦稻11’,占资源总数的5.31%;中抗品种29份,占总数的12.83%;中感品种为63份,占总数的27.88%;感病品种99份,占总数的43.81%;高感品种为‘合江11号’‘东农420’‘牡丹江31号’‘合江10号’‘东农419’等23份,占资源总数的10.18%,但没有发现免疫品种。     

解淀粉芽胞杆菌K103对黄瓜穴盘苗的促生作用

为了探明解淀粉芽胞杆菌（Bacillus amyloliquefaciens）K103对黄瓜穴盘苗的促生效果及作用机理,以草炭、蛭石、珍珠岩混合物料为基质,播种前基质接种K103,测定黄瓜穴盘苗生长发育参数,并采用454焦磷酸测序技术分析穴盘苗根际细菌群落结构和多样性。结果表明：解淀粉芽胞杆菌K103具有较高的固氮和溶解有机磷活性;基质接种K103提高了黄瓜穴盘苗根系活力和矿质养分吸收积累量,促进黄瓜生长;K103可在黄瓜穴盘苗根际定殖,并显著提高了根际食菌蛭弧菌,鞘氨醇单胞菌CHNTR37、CL01,德氏嗜酸菌,鹰嘴豆中慢生根瘤菌等9种细菌的相对丰度,这些细菌对植物多具有促生潜力。     

Determination of Festuca filiformis seedbank characteristics,seedling emergence and herbicide susceptibility to aid management in lowbush blueberry (Vaccinium angustifolium)

Festuca filiformis is a common perennial grass in lowbush blueberry fields, but little is known about the general biology, seedbank characteristics, seedling recruitment or susceptibility of seedlings to currently registered herbicides. The objectives of this research were to determine (i) the presence of F. filiformis seedbanks in lowbush blueberry fields, (ii) whether F. filiformis seedbanks accumulate near the soil surface in lowbush blueberry fields, (iii) the dormancy status of fresh F. filiformis seeds, (iv) the temporal patterns of seedling recruitment in established F. filiformis populations, (v) whether F. filiformis has a vernalisation requirement for flowering in lowbush blueberry and (vi) susceptibility of F. filiformis seedlings to various herbicides currently registered in lowbush blueberry. Festuca filiformis formed a seedbank in lowbush blueberry fields, with an average of 1660 ± 272–5680 ± 1409 seedlings m^?2 emerging from soil cores collected from two infested fields. Most seeds were located at the soil surface, providing opportunities for seedbank management through predation or burning. Fresh seeds lacked dormancy and readily germinated, although germination was reduced by dark conditions. New seedlings emerged in spring and autumn and required vernalisation to flower. Seedlings were susceptible to several currently registered herbicides in lowbush blueberry, although mortality rates were highest in plants treated with glufosinate, flumioxazin, glufosinate + flumioxazin and terbacil. Growers should avoid movement of seeds on machinery, and additional research should be conducted to determine the effects of registered herbicides on F. filiformis seedling recruitment under field conditions in lowbush blueberry.