冬季作物种植对双季稻根系酶活性及形态指标的影响

基于湖南长沙7a定位试验,以冬闲为对照,研究了冬种马铃薯、紫云英及油菜为前茬作物对早、晚稻根系酶活性、形态指标及产量的影响.结果表明,与冬闲相比,冬种作物后早、晚稻根系丙二醛(MDA)含量增加,但其根系的活性氧清除能力更强(SOD、POD和CAT活性高),能够在一定程度上缓解膜脂过氧化作用带来的伤害;冬种不同作物对早晚稻根系形态的影响表现不一.冬种马铃薯和紫云英处理在早稻生育后期的根系优势明显,并能在一定程度上促进晚稻根系生长,双季稻总产量较对照分别增加6.29％和7.76％,而冬种油菜抑制了晚稻根系生长,导致晚稻产量及双季稻总产分别降低6.31％和1.96％;相关性分析表明,灌浆期较高的根长、根数、根体积和根表面积是冬种作物改善双季稻产量的主要原因.综合来看,冬种马铃薯和紫云英对于促进双季稻根系生长,提高稻谷产量具有重要作用,而冬种油菜则不利于提高双季稻的稻谷生产力.     

超高产杂交稻光合特性的研究

比较了超高产杂交稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）Ｘ０７Ｓ／紫恢１００和两优培九与多年来大面积推广的杂交稻汕优６３的光合功能和抗光胁迫能力。结果表明,超高产杂交稻Ｘ０７Ｓ／紫恢１００和两优培九的净光合速率（Ｐｎ）分别比汕优６３高９．１％和１１．９％,而其蒸腾速率（Ｔｒ）分别比汕优６３低３７．４６％和３１．４２％,此外,其水分利用效率（ＷＵＥ）分别比汕优６３高出７４．２％和６３．５％;经强光（２０     

不同栽培条件下南方红豆杉生长特性研究

以4～6年生南方红豆杉为材料,对其不同栽培条件下地径、冠幅、株高、当年抽高、当年侧枝数及总侧枝数等生长特性进行了研究。结果表明:南方红豆杉4～6年生幼林生长量随年龄增大而增加,但其增加的趋势变缓,生长速度变慢;耕作农田中南方红豆杉生长最好,土壤板结未耕作农田生长较差,去除上层20cm耕作土的农田最差;南方红豆杉纯林生长好于落叶阔叶林下(林分郁闭度0.6～0.7),且种植密度越大差异越明显;南方红豆杉落叶阔叶林下套种及纯林生长量均随栽培密度减小而增大,不同栽培密度相差越大,生长量差异越明显。     

垄厢栽培对水稻根系特性与土壤物理性质的影响

为探究不同栽培方式对水稻根系特性与土壤物理性质的影响,为水稻垄作栽培技术提供依据,在湖南浏阳市开展了双季水稻大田小区试验.结果 表明:相比平作栽培,垄作栽培显著提高了早稻孕穗期根总长、根体积和早稻各时期、晚稻分蘖盛期的根系伤流强度,晚稻齐穗期根总长、根表面积、根体积分别显著增加36.9％、41.1％、44.9％;厢沟栽...     

不同水分管理模式下免耕抛秧水稻立苗期根系生长特性

在免耕条件下,对3种水分管理模式(水层淹灌、干湿交替灌溉和湿润灌溉)的立苗期根系特性进行了研究。结果表明,除抛栽后第2天,无论晚季或早季,整个立苗期干湿交替灌溉处理的根冠比、单株根生物量、总根数、白根数、一次分枝数量、根系活力、发根力均显著或极显著高于水层淹灌和湿润灌溉处理。水层淹灌处理利于二次分枝根的发生与根系的伸长。湿润灌溉处理更能促进早季稻根毛区生长。     

根系温度对甜椒生理特性的影响

甜椒苗期的最适根温为２５－３０℃。根温不适宜时,叶片生长明显减慢,光合速率下降,以致干物质积累减少。根温低的甜椒气孔呈前反馈式反应,根温高的气孔则呈反馈式反应,部分关闭和导度降低,胞间ＣＯ２分压减小,净光合速率降低。     

干旱条件下小麦根系的形态解剖学研究

经历严重干旱危害的冬小麦,返青至拔节期分布于耕层以内密集根系都已枯黄萎缩,其表皮细胞全部剥落,皮层细胞也严重受损,只有内部输导组织仍然健全,表明上层根此时已丧失了吸收功能。而位于深层的根由于所处土层较为湿润,外观为嫩白色,根的表皮和皮层细胞健全,春季降水（≥２０ｍｍ）后,上层已受扣迪的根不能恢复其原有的表皮和皮层组织,但能从分蘖节处产生新的次生根,恢复其吸收功能。     

氯化镉对葡萄根系线粒体特性与根系活力的影响

以巨峰、玫瑰香、龙眼和泽香4个葡萄品种一年生扦插苗为试材,研究了氯化镉（CdCl₂）处理后葡萄根系线粒体过氧化氢（H₂O₂）、膜通透性转换孔（MPTP）、膜电位（Δψ）、细胞色素C（Cyt c）及根系活力的变化.结果表明：4个葡萄品种经0.5 mmol·L^-1的CdCl₂处理后,根系线粒体H₂O₂含量上升,MPTP开放程度增大,Δψ降低,Cyt c含量下降,根系活力明显降低;其中,H₂O₂含量和Cyt c 含量由高到低的顺序为：巨峰＞泽香＞玫瑰香＞龙眼,而根系活力、MPTP和Δψ由高到低的顺序为：龙眼＞玫瑰香＞泽香＞巨峰.表明巨峰葡萄根系活力比其他品种更易受到CdCl₂的影响,而龙眼葡萄根系活力在4个品种中受CdCl₂影响最小.     

超高产杂交稻光合特性的研究

比较了超高产杂交稻(Oryza sativa L.)X07S/紫恢100和两优培九与多年来大面积推广的杂交稻汕优63的光合功能和抗光胁迫能力.结果表明,超高产杂交稻X07S/紫恢100和两优培九的净光合速率(Pn)分别比汕优63高9.1%和11.9%,而其蒸腾速率(Tr)分别比汕优63低37.46%和31.42%,此外,其水分利用效率(WUE)分别比汕优63高出74.2%和63.5%;经强光(2 000μmol photons@m-2@s-1)处理2 h之后,X07S/紫恢100和两优培九的光系统Ⅱ光化学量子效率分别上升28.3%和37.0%,荧光光化学猝灭系数分别升高46.2%和18.0%,而汕优63的这两项参数值却变化很小;同时,X07S/紫恢100和两优培九的非光化学猝灭系数均下降50%左右,而汕优63则上升近50%,表明超高产杂交稻较高的光合能力、水分利用效率以及较强的抗光抑制能力可能是其高产的生理基础.     

刺芹侧耳生长条件和栽培特性的研究

对刺芹侧耳[Pleurotus eryngii(DC.ex Fr.)Quel]生长条件与栽培特性进行了分析.结果表明:刺芹侧耳菌丝生长的适宜pH值为pH 5～pH 7,最适pH值为pH 6;黑暗环境有利于菌丝生长,光照对菌丝生长具有抑制作用;菌丝生长适宜的碳源为可溶性淀粉、葡萄糖和蔗糖,适宜的氮源为蛋白胨和钼酸铵,葡萄糖和蛋白胨的适宜浓度分别为50和1 g·L-1;在马铃薯黄豆粉培养基、黄豆粉玉米粉培养基和马铃薯蛋白胨培养基中可较好地形成菌丝球.采用液体菌种栽培,菌丝的生长速度比使用玉米固体菌种快,其中用马铃薯黄豆粉液体菌种栽培,菌丝生长最快;使用马铃薯蛋白胨液体菌种在木屑棉籽壳混合培养料中栽培,可获得菌柄长菌盖大的子实体,而且产量高.     

Critical Yield Factors for Achieving High Grain Yield in Early-Season Rice Grown under Mechanical Transplanting Conditions

Double-season rice cropping systems occupy a large portion of the rice production area in southern China. Because the problem of insufficient labor, mechanical transplanting (in contrast to the manual transplanting) was become more attractive in double-season rice system. However, the decisive yield factors which resulting in high grain yield of early-season rice are unclear under mechanical-transplanted conditions. In present study, the field experiments were conducted in the early season in 2017 and repeated in 2018 in Santang Town, Hunan Province, China. Ten early season rice cultivars (Zhuliangyou 819, Lingliangyou 268, Lingliangyou 104, Luliangyou 996, Xiangzaoxian 24, Xiangzaoxian 32, Xiangzaoxian 45, Xiangzaoxian 42, Zhongjiazao 17, and Zhongzao 39) were used as materials in this study. The difference in grain yield and closelyrelated agronomic and physiological traits of ten tested cultivars were compared. The range of yields (t ha^–1 at 86% dry matter) in 2017 was 6.2 to 8.7 (mean 7.8) and in 2018 was 6.5 to 8.4 (mean 7.8). Grain weight and pre-heading biomass accumulation had potent significant positive correlations with the grain yield. The greater pre-heading biomass accumulation was major attributed to higher apparent radiation use efficiency. Our results suggested that early-season rice cultivars to achieve the high grain yield in mechanical-transplanted conditions depends on apparent radiation use efficiency in the pre-heading period and higher grain weight.     

施肥对水稻产量和稻田土壤理化性质的影响

稻田土壤中养分的平衡主要取决于养分的输入与输出,其又主要受肥料的输入与植物所带走的养分所制约。不同的肥料品种、不同的施肥时期都影响养分在土壤中的吸收、转化与淋失,从而影响养分的输入与输出。稻田土壤生态系统中养分循环的研究已有很多报道。主要是不同耕作制度、不同施肥水平下,各输入输出因子的研究以及对土壤肥     

再生稻腋芽萌发的生态条件研究

再生稻在热带和亚热带产稻国都有种植,并为水稻科学家所关注。本世纪30年代,四川农学院杨开渠教授首先对再生稻作了系统研究。70年代南方稻区对再生稻的研究深入到品种再生力的遗传与选育,腋芽的形态、生育特点、营养生理、促芽肥施用时期和数量、田间     

Genotypic Variation in Root Growth Angle in Rice (Oryza sativa L.) and its Association with Deep Root Development in Upland Fields with Different Water Regimes

Deep root development, which is important for the drought resistance in rice (Oryza sativa L.), is a complex trait combining various root morphologies. The objective of this study was to elucidate genotypic variation in deep root development in relation to morphological indicators such as vertical root distribution and root growth angle. Two experiments were conducted: one on upland fields, and one in pots and fields. In experiment 1, the root systems of six rice cultivars on upland fields were physio-morphologically analyzed under different water regimes (irrigated and intermittent drought conditions during panicle development). In experiment 2, cultivar differences in root growth angles were evaluated with 12 cultivars using the basket method under irrigated conditions. No cultivar × environment interactions were found for total root length or deep root length between irrigated and drought conditions in experiment 1. This suggests that constitutive root growth, which is genetically determined, is important for deep root development under intermittent drought conditions during reproductive stage. Among root traits, the deep root ratio (i.e., deep root weight divided by total root weight) was most closely related to deep root length under both water regimes. This suggested that vertical root distribution constitutively affects deep root length. Significant genotypic variation existed in the nodal root diameter and root growth angle of upland rice in experiment 2. It was considered that genotypes with thick roots allocated more assimilates to deep roots through root growth angles higher to the horizontal plane on upland fields. This is the first report on genotypic variation in the root growth angle of rice on upland fields. It should prove useful for rough estimations of genotypic variation in the vertical root distribution of upland rice because root growth angle is rapidly and easily measured.     

稻田蜘蛛优势种对飞虱对叶蝉控制力的分析

系统调查结果表明,长沙地区早稻田中,蜘蛛优势种相对稳定,在水稻各生育期内均为拟水狼蛛和食虫沟瘤蛛,并无更替现象,采用灰色关联分析法,研究了长沙地区稻田蜘蛛优势种群对飞虱,叶蝉种群数量的控制程度,结果表明拟水狼蛛和食品沟瘤蛛对飞 虱,叶蝉种 数量影响最大,其次为锥腹肖蛸和八斑鞘腹蛛,当拟水狼蛛与飞虱之比为1：20．2,食虫沟瘤蛛与飞虱之比为1：14．5以上时,蜘蛛对飞虱显示出明显的控制力。     

Much Improved Water Use Efficiency of Rice under Non-Flooded Mulching Cultivation

Water shortage is increasingly limiting the luxury use of water in rice cultivation. In this study, non-flooded mulching cultivation of rice only consumed a fraction of the water that was needed for traditional flooded cultivation and largely maintained the grain yield. We also investigated the growth and development of rice plants and examined grain yield formation when rice was subjected to non-flooded mulching cultivation. One indica hybrid rice combination was grown in a field experiment and three cultivation methods, traditional flooding （TF）, non-flooded straw mulching cultivation （SM） and non-flooded plastic mulching cultivation （PM）, were conducted during the whole season. Grain yield showed that there was no significant difference between SM and TF rice, but the grain yield of SM cultivation was significantly higher than that of PM. The tiller numbers were inhibited in the early stage under non-flooded mulching cultivation, but the situation was reversed at the later period. Both SM and PM rice reduced dry matter accumulation of shoot, but increased root dry weight, enhanced the remobilization of assimilates from stems to grains and increased the harvest index. During the middle and later grain filling period, mulched plants showed a faster decrease in chlorophyll concentrations, photosynthetic rates of flag leaves and root activity than TF rice, indicating that non-flooded mulching cultivation enhanced plant senescence. In comparison, SM treatment produced higher grain yield and, more dry matter accumulation and panicle numbers than the PM treatment. The overall results suggest that high yield of non-flooded mulching cultivation of rice can be achieved with much improved irrigaUonal water use efficiency.     

不同供水条件下水稻幼苗根系形成的遗传分析

利用分子标记图谱对溶液培养与旱作培养（纸培养）下的水稻（Oryza sativa L.)幼苗的种子根与最长不定根长,不定根数,总根干重,根冠比等性状进行了基因定位与遗传分析。4种参数共检测到6个数量性状位点（quantitative trait loci,QTLs)与22对上位性互作位点,其中溶液培养中的最长不定根长,总根干重和旱作培养中的总根干重检测到的QTLs位点对总变异的贡献率分别为20％,23％和13％左右;旱作培养中的最长不定根长,不定根数,根冠比和溶液培养中的根冠比仅检测到上位性位点,对表型变异的贡献率在12％－61％之间,溶液培养与旱作条件下没有一个或一对检测到的QTL或互作位点完全相同,提示溶液培养和旱作条件下影响幼苗根系生长的遗传机制差异,上位性作用对旱作培养条件下的根生长具重要影响。     

略论稻田养鱼与农田生态

稻田养鱼能够挖掘稻田生态系统的生产潜力 ,既提高稻谷产量又增加淡水鱼产量 ,又为发展养鱼提供大量优质鱼种。稻鱼群落能够产生单一种稻所不能有的经济、生态和社会诸方面的综合效益 ,稻田养鱼为合理地利用土地资源提供了一种特殊的、最佳的生态模式。1　稻田养鱼在农田生态系统中的作用农田的水、土、光、热和气等非生物因素和动物、植物、微生物等生物因素密切地相互关联、相互依存、相互制约 ,形成一个在功能上统一的系统 ,即农田生态系统。在这个系统内 ,生物群落同其生活环境进行着能量、物质转化和循环。稻田是一个典型的人工生态系…     

灵芝胞内三萜高产菌株的筛选及发酵条件的优化

通过摇床培养实验,从22个灵芝菌株中筛选出三萜高产菌株GL31,通过单因子和正交试验优化了该菌株生产胞内三萜的发酵条件,包括碳源、氮源、无机盐,初始pH,装液量,接种量,发酵时间等。同时研究了GL31发酵过程中生物量、胞内三萜含量及胞内三萜产量的变化曲线,发现该菌株在摇床培养过程中第84h时菌丝内三萜产量高达3.51×102g/100mL;另外先摇床培养84h后再静止培养144h的菌丝三萜含量,菌丝三萜产量分别比仅摇床培养84h的菌丝三萜含量,菌丝三萜产量提高了48.6%和65%,该结果说明静置培养的方式有利于提高菌丝总三萜的含量。且将两种发酵方式菌丝总三萜的最高产量比较,发现先摇床后静置培养的菌丝总三萜最高产量高于仅摇床培养。     

水稻抗寒剂的效应及其施用技术

用KNO3（5g/L)和Na2HPO4(2g/L)及KH2PO3（2g/L)组合成抗寒剂（I）,混合比为1：1：1处理水稻种子和喷施幼苗能减轻早春寒害对幼苗的损伤;在寒露风来临之际,用KH2PO4（10g/L),Na2HPO4(2.5g/L)和尿素（10g/L)组成的抗寒剂（II)混合比为1：1：1喷施稻叶面能提高植株的抗冷性,促进颖花开裂,增加受精率和结实率,可以减轻寒露风对水稻产量的影响。