甘蓝型油菜自然群体苗期磷效率分析及磷高效优异种质筛选

为了筛选磷高效优异种质，研究油菜磷高效遗传，以甘蓝型油菜自然群体400个品种为试验材料，通过营养液培养方法进行了两轮苗期磷效率评估（分别命名为试验Ⅰ和试验Ⅱ）。该群体在低磷和正常磷处理下地上部干重、根系干重、根冠比、主根长和磷效率系数均呈现正态分布特征，品种间存在较大的基因型变异。以低磷处理地上部干重和磷效率系数为筛选指标，在试验Ⅰ中分别筛选出磷高效和低效候选品种各17份和13份，在试验Ⅱ中分别筛选出磷高效和低效候选品种各17份和18份。结合试验Ⅰ和Ⅱ，确定苗期磷高效候选品种32份，磷低效候选品种31份，可用以开展后续研究。     

增强的紫外线-B辐射对水稻秧苗生长的影响

以不同类型的 10个水稻品种 (组合 )为材料 ,研究了增强的UV -B辐射对水稻秧苗生长的影响。研究表明 ,增强的UV B辐射会导致水稻秧苗株高矮化、分蘖数减少、主根长减短、根数减少、地上部和地下部干物质重减少、叶面积减小。所考察的指标中 ,分蘖数和地下部干重可作为水稻抗UV B辐射增强种质筛选的关键指标     

苗期甘蔗氮高效基因型评价指标的筛选

本研究通过低氮压力选择,筛选出甘蔗氮高效种质,分析影响甘蔗氮高效的重要指标,为甘蔗氮高效育种及栽培提供理论依据。以58份甘蔗种质资源为材料,在苗期采用正常供氮（2 mmol/L N）和低氮（0.2 mmol/L N）处理,分析甘蔗植株形态、干重及氮素在各器官中累积分配的特征。通过主成分分析方法筛选影响甘蔗氮高效利用的重要指标,通过聚类分析对58份种质进行聚类。结果表明,低氮（0.2 mmol/L N）处理可以明显从植物形态区分不同种质的氮利用差异,58份种质低氮条件下的干重范围为0.64~14.75 g/株,氮累积量为5.53~63.00 mg/株,氮利用率范围为115.40~279.30 g/g。对低氮压力下甘蔗干重及氮累积等25个指标进行主成分分析后,提取出4个主要成分,总贡献率为92.35%。通过高、低氮条件下与氮利用效率有关的氮转移系数及基因潜力等19个指标分析后提取出5个主成分,总贡献率为82.21%。影响甘蔗氮高效的重要指标有甘蔗的干重（全株、叶、根）、氮累积量（全株、叶、茎）、氮利用率（全株、叶）、叶的相对氮利用率、茎的基因潜力、茎的相对干物质量和茎的相对氮累积量。经聚类分析后初步将58份甘蔗种质分为氮高效基因型、偏氮高效基因型、偏氮低效基因型和氮低效基因型。     

5个马铃薯品种组培幼苗的磷效率差异研究

试验以5个生产用马铃薯品种脱毒试管苗为材料,采用组织培养的方法,初步研究了茎切段在正常磷及低磷培养基中生长30 d时幼苗的磷营养效率差异,为筛选出适宜于生产用的磷高效马铃薯品种奠定了基础。试验结果表明,5个马铃薯品种幼苗在正常磷和低磷胁迫下对磷素的吸收和利用能力均存在明显的基因型差异。利用各品种幼苗的磷效率指标(植株干重、鲜重、吸磷量、磷利用效率)的相对指标(低磷处理的结果/正常磷处理的结果×100)进行聚类分析(类平均法)的结果表明,大白和I-1035属于磷高效基因型品种,中农Ⅷ是磷低效基因型品种,凉薯97和疫不加则属于中间类型品种。     

甘蓝型油菜种质氮素营养效率的鉴定及评价指标筛选

为建立甘蓝型油菜种质氮素营养效率的鉴定及评价方法,筛选合理的次级评价指标和氮素营养高效基因型,在田间小区试验条件下设置低氮(45 kg/hm2)、中氮(180 kg/hm2)和高氮(270 kg/hm2) 3个施氮水平,测定了416份不同生态类型甘蓝型油菜种质植株性状及氮素吸收效率(NAE)、氮素利用效率(NUE)和氮收获指数(NHI)。各性状在不同氮素水平下对氮的敏感性不同,低氮下第一次有效分枝数的变异程度表现为最大,单株籽粒重次之;中氮和高氮处理水平下单株籽粒重的变异程度均表现为最大,低氮胁迫加大了种质间的差异。油菜种质氮素营养效率基因型间差异明显,表现中效类型的种质最多,高效和低效的较少。油菜种质间成熟期NAE的鉴定与评价应选择在低氮处理下,以单株籽粒重、单株地上干重和株高为间接指标进行选择效果明显;油菜种质间成熟期NUE的鉴定与评价应选择在高氮处理下,以单株地上干重、第一次有效分枝数、单株籽粒重和每角粒数为间接指标进行选择效果明显;油菜种质间成熟期NHI的鉴定与评价应选择在低氮处理下,以单株籽粒重、单株地上干重和茎基粗为间接指标进行选择效果明显。     

不同大豆品种田间结瘤固氮有效性的评价

利用相关和通径分析对田间种植的４０份大豆品种（系）的结瘤固氮性状（结瘤分级，有效瘤数，有效瘤干重，有效结瘤指数，植株干重和植株全氮含量）的研究表明：有效瘤数，有效瘤重和有效结瘤指数可以有效地作为对大豆固氮种质的评价指标，其相对重要性为有效瘤重＞有效瘤数＞有效结瘤指数。在此基础上并结合籽粒产量因子筛选出２份结瘤固氮及产量较高的种质。研究同时也获得了七份在有效瘤重与有效瘤数或有效瘤重与效结瘤指数上表现     

新疆冬小麦苗期耐低磷指标的筛选

为了筛选快速评价冬小麦苗期耐低磷性的指标,测定了两种磷素水平下15个冬小麦品种苗期的株高、根长、根数、根干重、茎干重、植株磷积累量等6项生理指标.相关分析和通径分析表明,茎干重和根干重对植株磷积累量有极显著的直接作用,茎干重是影响植株磷积累量的最重要的性状;通过主成分分析可将6个单项生理指标综合成3个相互独立的综合指标,小麦在低磷条件下的适应性与植株干物质特征最为密切.本研究结果表明,植株磷积累量、茎干重、根干重、根数可以作为小麦苗期耐低磷基因型快速筛选的指标.     

小麦耐低磷基因型的筛选

为发掘新的耐低磷小麦种质,利用磷源液相控制释放系统,通过相对生物量、根冠比和根部结构特征等形态指标,对41份小麦材料进行耐低磷种质筛选.结果表明,供试材料中,231104、231106和231122的相对生物量均在80%以上,根系发达,根毛长且密.其中,231122的相对生物量接近100%,在低磷胁迫下根部干重和根冠比明显高于正常供磷对照.用231个SSR标记进行多态性分析发现,它们与洛夫林10号和小偃54的多态率分别超过60%和58%.由此说明,231104、231106和231122是不同于洛夫林10号和小偃54的耐低磷种质,且能在低磷胁迫下优先保证根部生长,并调整根的形态结构,以利于吸收磷素,满足植株正常生长的需要.     

氮高效水稻品种苗期耐低磷种质的筛选与鉴定

以先前通过田间试验筛选出来的36个氮高效水稻品种为供试材料,在苗期进行了耐低磷筛选,并对获得的3个耐低磷和2个低磷敏感品种响应磷素胁迫的生理机制进行了初步研究。结果表明:1)正常供磷和低磷条件下,所有调查性状的相对值(低磷/正常供磷)中,相对根系干质量、相对地上部干质量、相对根冠比和相对分蘖数均具有较大的品种间变异(变异系数分别为16.9%、10.9%、11.4%、16.3%)。相关分析表明,它们呈显著或极显著正相关。因此,这4个性状可以作为水稻苗期耐低磷筛选的评价指标。2)在低磷条件下,筛选出的3个耐低磷品种比2个低磷敏感品种的根系生长旺盛且活力强,P吸收动力学参数中Km、Cmin小,而Vmax大,酸性磷酸酶(APase)活性升幅大,磷效率在两者之间也存在显著差异。同时,不同耐低磷品种适应低磷胁迫的调节机制也有所不同。表明筛选氮磷双高效的水稻品种是可行的,同时也为后续基因定位和遗传机制的研究提供了材料和生理学依据。     

湖南长沙一季晚稻旱稻孢囊线虫发生动态及危害损失

目的 为了解旱稻孢囊线虫的田间发生动态,明确旱稻孢囊线虫的防治指标。方法 2016–2018年对长沙地区一季晚稻的旱稻孢囊线虫发生规律进行了定期定点调查,采用田间小区接种的方法测定了其不同群体密度下一季晚稻的损失,建立了旱稻孢囊线虫群体密度与产量损失的回归方程。结果 旱稻孢囊线虫发生动态调查结果表明,孢囊高峰期主要出现在水稻分蘖期末、孕穗期和黄熟期,推测旱稻孢囊线虫在长沙地区一季晚稻每年发生3代。小区接种试验测产结果表明,旱稻孢囊线虫对水稻株高、有效穗数、实粒重、结实率等农艺性状产生不利影响;每1mL土壤接种卵量≥4个,旱稻孢囊线虫危害较为严重,被害株实粒重损失在19.4%以上,应采取相应的防治措施。结论 我们分析了旱稻孢囊线虫发生世代数的影响因素和防治指标。研究结果可为指导长沙地区旱稻孢囊线虫防治提供理论依据。     

Difference in Grain Yield and Quality among Tillers in Rice Genotypes Differing in Tillering Capacity

A japonica variety and its iso-allelic mutant with high tillering ability were used to investigate the differences in grain yield and quality among different tillers. There was a distinct difference in panicle weight among tillers during grain filling for both genotypes, with Xiushui 11 having a greater increase rate in panicle weight, and being earlier in reaching the maximum panicle weight than the mutant. There was a great significant difference between the two genotypes in grain yield and its components, with Xiushui 11 having higher grain yield, more grains per panicle, higher filled grain percentage and grain weight than the mutant for each type of tiller. Moreover, a significant difference was found in grain yield and yield components among different tillers for both genotypes, with grain number per panicle showing the greatest variation over tillers among all yield components. Compared with Xiushui 11, the mutant had higher brown rice rate and greater ratio of length to width of brown rice, and lower chalky rice rate, amylose content, and protein content of rice. Furthermore, there was a significant difference in grain quality among tillers within a plant for both genotypes, with later initiated tillers being lower in chalky rice rate, amylose and protein contents than early initiated ones. The variation of most quality parameters among tillers within a plant was markedly larger for the mutant than for Xiushui 11.     

Characterization and Selection of Phosphorus Deficiency Tolerant Rice Genotypes in Sri Lanka

Phosphorus（P） deficiency in soil is a major constrain for rice production. An important set of rice genotypes（landraces, old improved and new improved varieties） were screened for P deficiency tolerance in two major cropping seasons of Sri Lanka, in 2012. The Ultisol soil, which was collected from a plot cultivated with rice without fertilizer application for past 40 years（P₀） at the Rice Research and Development Institute（RRDI）, Bathalagoda, Sri Lanka, was used as the potting medium for greenhouse trials. Two field trials were conducted in the same plots at RRDI. Both P₀ and P₃₀（30 mg/kg P₂O₅） conditions were used in the two greenhouse trials. At the early vegetative（three weeks after transplanting）, late vegetative（six weeks after transplanting） and flowering stages, plant height and number of tillers per plant were recorded. At the flowering stage, shoots were harvested and shoot dry weight, shoot P concentration, shoot P uptake and P utilization efficiency were measured. All data were statistically analyzed using analysis of variance, regression and cluster procedures. The measured parameters were significantly different between P₀ and P₃₀ conditions（P < 0.05）. Higher shoot dry weight was reported by the rice genotypes H4 and Marss under P₀ conditions. The regression analysis between shoot dry weight and P utilization efficiency revealed that the studied rice genotypes could be categorized to three P deficiency tolerance classes. A total of 13 genotypes could be considered as highly tolerant and 4 genotypes as sensitive for P deficiency. These results could be used to select parental genotypes for breeding and genetic studies and also to select interesting varieties or landraces for organic rice production.     

海南山栏稻农艺特征与抗旱生理特性研究

研究了１２个山栏稻原始种质的主要农艺性状、品质特征及抗旱生理特性，并与水稻不同类型的对照进行比较分析。结果表明，在旱地栽培条件下，山栏稻的穗长、穗粒数、衙粒重及单株产量均显高于对照水稻．但不时也表现高杆、穗颈过长、移片大且披垂等不良性状。在品质方面，山栏稻糙米粗蛋白含量、１７种氨基酸含量及２种必需氨基酸含量显高于水稻对照。山栏稻种子在高渗溶液中的发芽率、离体叶片保水率、质膜稳定性和分蘖秆长整齐     

高氮素籽粒生产效率类型籼稻品种的一些相关性状

 在群体水培条件下,以国内外不同年代育成的常规籼稻代表品种（2001年为88个、2002年为122个）为材料,对植株的干物质量、氮素含量、产量及其构成因素、生育期、株高、成穗率、穗部性状等进行了测定。采用组内最小平方和的动态聚类方法将供试品种的氮素籽粒生产效率（NUEg）分为 6种类型,研究不同NUEg类型品种生育期、株高、成穗率、穗部性状的基本特点。结果表明：1）高NUEg品种生育期（特别是播种至抽穗）较短,NUEg与全生育期、播种至抽穗天数呈显著负相关; 2)不同NUEg类型品种间株高无显著差异,株高与NUEg无密切关系;3）高NUEg类型品种分蘖成穗率高,分蘖成穗率与干物质运转及氮素运转关系密切;4）高NUEg类型品种穗长较短,着粒密度较大。     

水分管理对免耕抛秧水稻根系生长及产量的影响

研究了水分管理对免耕水稻根系生长和产量的影响。结果表明,干湿交替灌溉对根系的伸长、生长、生理及分布具有较大影响,水稻各生育期干湿交替灌溉处理水稻单株根干质量、单株生物量、根半径、根表面积、总根数、根系活力、超氧化物歧化酶活性均显著高于淹水淹灌。干湿交替灌溉处理实收产量显著高于淹水淹灌,增产主要因子是有效穗数、每穗粒数和结实率。灌浆盛期干湿交替灌溉处理单株生物量、根半径、根表面积、总根数、超氧化物歧化酶活性均显著高于湿润淹灌,水稻产量差异则不显著。     

Genotypic Differences in Growth and Physiological Responses to Transplanting and Direct Seeding Cultivation in Rice

The field experiments were conducted to investigate the growth and physiological responses of six super hybrid rice combinations to two planting methods,transplanting(TP) and direct seeding(DS) during 2006-2007 and 2007-2008. The 1000-grain weight and number of tillers per plant at the early growth stage,the maximum quantum yield of PSII(Fv/Fm) and transpiration rate(Tr) were higher in DS plants than in TP ones,whereas the grain yield,number of panicles per square meter,seed setting rate,net photosynthetic ...     

Effects of Soil Copper Concentration on Growth, Development and Yield Formation of Rice （Oryza sativa）

Pot experiments were conducted in 2002 and 2003 to investigate the effects of soil copper（Cu） concentration on growth, development and yield formation of rice by using the japonica cultivar Wuxiangjing 14 and hybrid rice combination Shanyou 63. The plant height, leaf number, elongated internode number and heading date of rice plants were not affected at soil Cu levels below 200 mg/kg, but affected significantly at above 400 mg/kg. The inhibitory effects on rice growth and development were increased with the increment of soil Cu levels. The grain yields decreased significantly with raising soil Cu levels. The main reasons for the grain yield reductions under lower soil Cu levels （100, 200 mg/kg） were mainly due to the decrease of number of spikelets per panicle, however, under higher soil Cu levels （more than 400 mg/kg）, both panicle number and number of spikelets per panicle contributed to the yield loss. The decreases of panicle number by Cu stress were mainly attributed to slow recovery from transplanting, delayed tillering and reduced maximum tiller numbers. The reduction of number of spikelets per panicle under soil Cu stress resulted from the decreases of both shoot dry weight （SDW） at the heading date and the ratio of spikelets to SDW. Total biomass at maturity decreased significantly with the increase of soil Cu levels, while economic coefficient showed non-significant decrease except under soil Cu levels above 800 mg/kg.     

肥床旱育稀植水稻单株生产力研究

研究汕优６３不同带蘖秧苗的结实性状及相互关系，表明旱育稀植水稻的结实性状与单株带蘖数呈二次曲线关系，与单株成穗数亦呈二次曲线关系，以单株带蘖２～３个、成穗８～９个秧苗综合性状好，产量高     

Relation of Root Growth of Rice Seedling with Nutrition and Water Use Efficiency Under Different Water Supply Conditions

The arid/semiarid regions contribute the forty- three percent of crop planted each year. In these regions, rice is mostly grown under rainfed conditions, where the chances plants to face drought are during the growing season. The primary determinant of cr…     

垄畦栽培水稻的产量、品质效应及其生理生态基础

以杂交稻协优9308和粳稻丙98110为材料,初步研究了垄畦栽培水稻产量、品质效应及其生理生态基础。与常规栽培相比,垄畦栽培时日温差(尤其是5～10 cm土层)、5 cm深处土层的氧化还原电位大于常规栽培。垄畦栽培水稻的加工品质、外观品质好, 水稻分蘖发生快,叶面积指数大,干物质积累多,上层根量大;其株高、穗长、分蘖成穗率小于常规栽培水稻,单位面积穗数、结实率、千粒重则高于常规栽培水稻。垄畦栽培水稻的抽穗期和齐穗期的叶绿素含量和光合速率、灌浆后期叶片中超氧化物歧化酶（SOD）、丙二醛（MDA）的含量与常规栽培水稻无显著差异。垄畦栽培水稻的产量,协优9308显著高于常规栽培水稻,丙98110则无显著差异。