不同类型甘薯光合光响应曲线拟合及比较分析

为研究甘薯光合光响应曲线的最适模型,运用4种常用模型对光合光响应数据进行曲线拟合,结果表明:直角双曲线模型和非直角双曲线模型得到的光饱和点要远远小于实测值,而指数模型虽然能较好地拟合出光饱和点和最大净光合速率,但其得到的光补偿点和暗呼吸速率值要远小于实测值,直角双曲线修正模型能更好地拟合甘薯光合光响应曲线。8个品种中,福薯2号和广薯87具有最高的净光合速率,是光合效能较好的两个甘薯资源。

食用、加工双优质高产型甘薯新品种福薯806的选育

福薯806是福建省农业科学院作物研究所以福薯604为母本,广薯87、福薯90916、福薯2号、龙薯710、胜利百号、金薯14等品种为父本进行集团杂交选育而成,该品种2020-2021年参加福建省甘薯区试,两年鲜薯平均产量38448.75 kg·hm^(-2),比对照广薯87增产6.43%;薯干产量10135.35 kg·hm^(-2),比对照广薯87增产11.74%;淀粉产量6610.05 kg·hm^(-2),比对照广薯87增产13.63%;干物率29.35%,淀粉率19.17%;薯块蛋白质含量0.78μg·hg^(-1),可溶性糖含量3.58%,胡萝卜素含量248μg·hg^(-1);中抗蔓割病,中感薯瘟。食味品质和外观鉴定综合评价,其中食味评分82.6分,比对照广薯87高2.6分;外观评分81.6分,比对照广薯87高1.4分,食用品质达到特优质品种水平,适合作为倒蒸地瓜干产品的原料薯。

甘薯新品种茎尖培养及病毒检测技术

为了优化甘薯茎尖培养方法,获得甘薯新品种脱毒试管苗。采用正交试验法,研究NAA、GA3和6BA三种因素对甘薯茎尖分化和植株再生的影响,筛选培养基最佳配方;在正交试验基础上,进一步考察不同甘薯品种在最佳培养基组合的茎尖分化和植株再生情况;并用RTPCR方法对成苗的甘薯品种再生株系进行病毒病(SPFMV、SPCSV、SPVG、SPVC和SPLV)检测。结果表明:各试验因素对福薯604茎尖分化成苗影响的主次关系为6BA>NAA>GA3,福薯604茎尖组培成苗的最佳组合为MS培养基+6BA 1.2 mg·L^-1+NAA 0.10 mg·L^-1+GA30.1 mg·L^-1,其茎尖组培苗萌芽率为93.3%、成苗率达50.0%。不同甘薯品种在最佳培养基组合条件下的茎尖分化情况表现不同,其中,福菜薯23和福薯116甘薯品种的茎尖分化和植株再生情况最好。不同甘薯品种试管苗经RTPCR检测,最终获得福薯8号、福薯34、福菜薯22、福薯916、福薯90、福菜薯23、福薯116、福薯317、福薯604、福薯16号、福薯33和福薯113等12份甘薯脱毒试管苗,可应用于实际生产。

我国马铃薯产量对施氮的响应及其影响因素分析

【目的】在全国及区域尺度上,定量评价马铃薯产量对施氮的响应及其影响因素,旨在明确不同条件下施氮对马铃薯产量的影响,为氮肥合理施用提供参考。【方法】通过搜集、筛选、整理已公开发表的有关我国马铃薯施氮产量效应的文献信息建立数据库,利用Meta分析这一综述性统计方法,以不施氮为对照,运用自然对数响应比来度量施氮对马铃薯产量的影响程度,并运用Meta回归分析和亚组分析来评价不同因素对施氮效果的影响。【结果】共搜集到符合本研究要求的文献52篇,从中获得220组数据,涵盖我国6个马铃薯主要种植区域,且不同研究结果间存在显著异质性。根据失安全系数法分析结果,本研究受发表偏倚的影响不明显,结论具有较高的可信度。Meta分析结果表明,与不施氮相比,施氮显著提高了我国马铃薯产量,整体增产幅度为31.1%,且不同基础产量间的施氮效果存在明显差异,在基础产量小于20 t/hm^2条件下,马铃薯产量与施氮量呈显著正相关。区域间的施氮效果存在显著差异,西南区施氮效果最佳,施氮产量增幅为42.6%,其次为东北区(40.6%)、中原区(37.2%)、华北区(34.7%)、华南区(17.7%)和西北区(12.1%)。在施氮水平较低时施氮方式对施氮效果没有明显影响,但在施氮量大于225 kg/hm^2时,基施+追肥方式的增产效应明显。在低种植密度(<5.25万株/hm^2)条件下,施氮增产率为35.4%,明显高于中密度(5.25~6.75万株/hm^2)和高密度(>6.75万株/hm^2)种植。施氮效果与土壤类型紧密相关,在黄棕壤、红壤、黑土、黄壤、黑钙土、水稻土和黑垆土上施氮增产效应显著,而在黄绵土上未达显著水平;土壤质地也影响氮肥效果,黏土施氮增产率为54.8%,高于砂土(46.5%)、砂壤土(28.0%)和壤土(26.0%)。在土壤pH 6.5~7.5、有机质含量<15 g/kg、全氮含量1~2 g/kg和有效磷含量<15 mg/kg的条件下,施氮的增产效应更明显。【结论】施氮对提升我国马铃薯产量有重要作用,施氮效果与土壤基础产量、区域、种植密度、土壤类型、质地、pH、有机质含量、全氮含量和有效磷含量密切相关。因此,各地区在制定马铃薯施氮方案时应充分考虑这些因素,以提高氮肥利用效率和增加马铃薯产量。

密度与施氮及其互作对冬作马铃薯产量和氮肥农学利用率的影响

【目的】探讨密度与施氮及其互作对冬作马铃薯产量和氮肥农学利用率(AEN)的协同调控效应,为冬作马铃薯高产高效栽培提供理论参考和技术支撑。【方法】以冬作马铃薯主栽品种闽薯1号为材料,采用田间裂区试验设计,主区设3种密度(4.76万、6.67万和10.96万株·hm^−2,分别以D4.76、D6.67和D10.96表示),副区设4个施氮水平(0、75、150和300 kg·hm^−2,分别以N0、N75、N150和N300表示),研究密度与施氮对冬作马铃薯产量、氮肥农学利用率(AEN)和叶片光合特性的影响。【结果】密度和施氮及其互作对马铃薯总产量和AEN均有显著影响,适当增密有利于提高马铃薯总产和AEN,其中D6.67处理产量最高,AEN则以D10.96处理最高。在N300水平下,D6.67和D10.96处理总产比D4.76处理分别提高21.3%和21.2%,AEN分别提高20.5%和49.2%,增幅比在其他施氮水平下明显,表明高氮水平下增密效果更显著。施氮显著提高了马铃薯产量,且在施氮量为150 kg·hm^−2时产量最高。在D4.76和D6.67条件下,N75和N150处理产量差异不明显,但在D10.96条件下N75处理产量显著降低。AEN随施氮量增加明显下降,相比N75处理,N150和N300处理的AEN分别下降41.2%和75.2%。与不施氮相比,施氮显著提高了叶片气体交换参数和相对叶绿素含量SPAD,而高密种植不利于叶片光合效率的提高,D10.96处理叶片净光合速率Pn均低于D6.67处理。相关性分析发现,叶片光合特性与马铃薯总产量之间均呈显著正相关。【结论】在本试验条件下,6.67万株·hm^−2和150 kg·hm^−2的处理组合产量最高(32.2 t·hm^−2),10.96万株·hm^−2和75 kg·hm^−2的处理组合AEN最高(156.5 kg·kg−1);高氮水平配合增密、中低密度配合减氮可作为协同提高冬作马铃薯产量和氮肥农学利用率的参考途径。

Physicochemical and Sensory Properties of japonica Rice Varied with Production Areas in China

Northeast of China and Jiangsu Province are major production areas of japonica rice in China.Rice from northeast of China is well-known for its good-eating and appearance quality,and that from Jiangsu Province is viewed as inferior.However,little is known concerning the difference in physicochemical and sensory properties of rice between the major two production areas.Analysis of 16 commercial rice samples showed marked differences in physicochemical properties,including chalky grain rate,contents of amylose and protein and pasting properties between the two main areas.Northeastern rice contained more shortchain amylopectin as compared with Jiangsu rice.However,Jiangsu rice is comparable to northeastern rice in terms of sensory quality including overall acceptability and textural properties of springiness,stickiness and hardness as evaluated by trained panel.Our results indicated the limitation of conventional index of physicochemical properties,and suggested the necessity of identification of new factors controlling rice sensory property.In addition,the taste analyzer from Japan demonstrates limitation in distinguishing the differences between northeastern and Jiangsu rice,and therefore needs localization to fit China.

Effects of Nitrogen Fertilization and Genotype on Rice Grain Macronutrients and Micronutrients

High nitrogen （N） input features China＇s intensive rice production system. To elucidate N and genotype effects on accumulation of macronutrients and micronutrients in grains of japonica rice, and to discuss its significance in rice production, a three-year field experiment involving six japonica rice varieties and seven N treatments were performed. Macronutrients （Ca, Mg, K, and Na） and micronutrients （Cu, Fe, Mn, and Zn） concentrations in brown and milled rice were measured using an atomic absorption spectrophotometer. For macronutrients, no consistently significant effect of N was detected in both brown and milled rice. For micronutrients, N showed significant effect, especially in lowering Zn accumulation in brown and milled rice. In addition, N tended to increase Fe concentration in milled rice. Genotype showed larger effect on distribution of minerals in milled rice than N. The high-yielding variety, Wuyunjing 7, accumulated larger proportion of Mg, K, and Zn in the milled rice as compared with the other five varieties and could be of value for rice breeding programs aiming at high nutritional quality. The results demonstrated differences in response to N between macronutrients and micronutrients, and are of significance for coping with ＇hidden hunger＇ both in humans and crops through agronomical practices.

Analysis of Variations in White-Belly and White-Core Rice Kernels Within a Panicle and the Effect of Panicle Type

This study aims to investigate the variation in occurrence of white-belly rice kernel（WBRK） and white-core rice kernel（WCRK） among different positions within a panicle. Twenty-four M4 mutants involved in four panicle types, namely the compact, intermediate, loose, and chicken foot panicle were used. They derived from a japonica rice cultivar Wuyujing 3. Considerable differences in morphological characters existed among the four types of panicle, especially in panicle length, the secondary branch number and ratio of grain number to total branch length. Marked differences were found in WBRK and WCRK among different positions within a panicle for all types of panicle. In general, grains located on the primary rachis and top rachis branches had higher WBRK and WCRK percentage than those on the secondary rachis and bottom rachis branches. WCRK exhibited larger variation among grain positions than WBRK did. Moreover, there was a significant difference in WCRK/WBRK among grain positions within a panicle, with primary rachis and top rachis branches having higher values than the secondary and bottom rachis. In addition, panicle type showed no significant effect on the pattern of WBRK and WCRK occurrence within a panicle. The results indicated the difference in mechanism of WBRK and WCRK formation in grain position within a panicle, and are valuable for breeding and agronomic practices aimed at lowering chalky grain rate.

Variation in Yield and Physicochemical Quality Traits among Mutants of Japonica Rice Cultivar Wuyujing 3

To select elite germplasms, 112 mutants derived from japonica rice cultivar Wuyujing 3 were evaluated. The yield components such as panicle number per square meter, grain number per panicle, and grain weight were measured. The quality traits such as percentage of chalky grains（PCG）, brown rice yield（BRY）, milled rice yield（MRY）, degree of milling（DM）, amylose content（AC）, protein content（PC）, and relationships among traits were inverstigated. Results showed that grain yield ranged from 2.15 to 12.49 t/hm2 with a mean of 6.4 t/hm2 and number of grains per square meter contributed for 94.64% in grain yield variation. For quality traits, all rice mutants had short size（grain length ≤ 5.5 mm） and bold shape（grain length to width ratio = 1.10-2.00）. Most of rice mutants（87.5%） had PCG values below 20%. All mutants had MRY values above 50%, AC values below 20%, and PC values below 10%. Percentage of chalky grains was significantly negatively correlated with MRY and positively correlated with DM. BRY and MRY were significantly negatively correlated with DM. PC was significantly and positively correlated with MRY and negatively correlated with DM, while AC had no significant correlation with these quality traits. It was concluded that there were 25 rice mutants which fulfilled the major requirements of Jiangsu standard japonica rice such as low percentage of chalky grains, low amylose content, optimal protein content, and which could be used as elite germplasms. Thus the mutants identified may lead to significant progress in improvement of rice quality.

福建甘薯病毒病病原鉴定及主要病毒多样性

【背景】病毒病是甘薯的一种重要病害,给甘薯生产带来了严重的经济损失,而生产中甘薯病毒病病原种类复杂多样。【目的】明确福建甘薯病毒病种类、分布及流行,对主要病毒进行多样性分析。【方法】从福建主要甘薯种植区采集病毒病样品,利用PCR/RT-PCR的方法对采集的样品进行病原检测,获得病毒序列,利用MEGA 6.0构建系统进化树进行遗传分析。【结果】从福建7个甘薯产区鉴定12种甘薯病毒,包括9种RNA病毒:甘薯羽状斑驳病毒(Sweet potato feathery mottle virus,SPFMV)、甘薯褪绿矮化病毒(Sweet potato chlorotic stunt virus,SPCSV)、甘薯G病毒(Sweet potato virus G,SPVG)、甘薯C病毒(Sweet potato virus C,SPVC)、甘薯2号病毒(Sweet potato virus 2)、甘薯褪绿斑病毒(Sweet potato chlorotic fleck virus,SPCFV)、甘薯潜隐病毒(Sweet potato latent virus,SPLV)、甘薯轻型斑点病毒(Sweetpotatomildspeakingvirus,SPMSV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV),3种DNA病毒:甘薯卷叶病毒(Sweet potato leaf curl virus,SPLCV),甘薯无症状1号病毒(Sweet potato symptomless virus 1,SPSMV-1),甘薯杆状DNA病毒B (SPBV-B)。SPFMV、SPCSV、SPVG和SPLCV检出率最高,分别为50.28%、41.90%、35.75%和24.58%,CMV检出率最低,为2.79%,未检测到甘薯C-6病毒(SweetpotatoC-6)和甘薯轻型斑驳病毒(Sweetpotatomild mottle virus,SPMMV)。福建甘薯主要以2-6种病毒复合侵染为主,单一侵染率占14.39%,2种以上复合侵染占85.61%。福建SPFMV分离物存在EA、O和RC3种株系,SPCSV分离物存在WA1种株系,未发现EA株系,甘薯卷叶病毒分属于2个不同的株系群。【结论】福建甘薯病毒种类多样,以复合侵染为主,且存在多种株系,遗传结构复杂。