石河子绿洲农业生态系统演替规律初探

研究分析玛纳斯河流域石河子绿洲农业生态系统演替规律结果表明,随着技术投入和市场的开放,绿洲农业生产力呈正向演替,而与之相应的生态环境部分呈逆向演替。人类活动是绿洲演替(正向或逆向)的根本动因,而绿洲所处的环境条件是加速其演替进程的关键,其中水资源时空分布及利用格局是主导因素。玛纳斯河流域农业生态系统良性演替需建立在绿洲资源要素时空优化配置及其协调开发利用上。     

钾对小麦旗叶蛋白水解酶活性和籽粒品质的影响

利用强筋冬小麦品种烟农15研究了钾素对小麦旗叶蛋白质含量和籽粒品质及有关酶活性的影响. 结果表明, 钾素有利于提高灌浆前期和中期小麦旗叶中可溶性蛋白质和游离氨基酸的含量, 增强内肽酶和羧肽酶的活性, 促进籽粒中游离氨基酸转化为蛋白质, 提高籽粒中清蛋白、球蛋白、醇溶蛋白和谷蛋白的含量, 改善籽粒营养品质和加工品质     

渗灌对番茄根系生长发育的影响

Four depth treatments of subsurface drip irrigation pipes were designated as 1) at 20, 2) 30 and 3) 40 cm depthsall with a drip-proof flumes underneath, and 4) at 30 cm without a drip-proof flume to investigate the responses of atomato root system to different technical parameters of subsurface drip irrigation in a glass greenhouse, to evaluate tomatogrowth as affected by subsurface drip irrigation, and to develop an integrated subsurface drip irrigation method for optimaltomato yield and water use in a glass greenhouse. Tomato seedlings were planted above the subsurface drip irrigationpipe. Most of the tomato roots in treatment 1 were found in the top 0-20 cm soil depth with weak root activity but withyield and water use efficiency (WUE) significantly less (P=0.05) than treatment 2; root activity and tomato yield weresignificantly higher (P=0.05) with treatment 3 compared to treatment 1; and with treatment 2 the tomato roots andshoots grew harmoniously with root activity, nutrient uptake, tomato yield and WUE significantly higher (P=0.05) oras high as the other treatments. These findings suggested that subsurface drip irrigation with pipes at 30 cm depth witha drip-proof flume placed underneath was best for tomato production in greenhouses. In addition, the irrigation intervalshould be about 7-8 days and the irrigation rate should be set to 225 m^3 ha^-1 per event.     

硫素对冬小麦籽粒蛋白质积累的影响

在0～20 cm土层有效硫含量为5.84 mg/kg地块上施硫,显著提高冬小麦根系和旗叶硝酸还原酶活性,增加旗叶总游离氨基酸和可溶性蛋白质含量,利于旗叶蛋白质的合成;施硫亦提高旗叶内肽酶和羧肽酶活性,加速旗叶蛋白质的降解.施硫67.5 kg/hm2促进籽粒谷蛋白积累,显著提高籽粒蛋白质含量,改善加工品质,增加籽粒和蛋白质产量,但对醇溶     

海南肾茶病原根结线虫的鉴定及对其寄主生长的影响

了解海南肾茶根结线虫的种类、特征及其对肾茶生长的影响.从感染线虫的肾茶根系中分离线虫的雌虫、雄虫与幼虫,用显微镜观察描述线虫特征并对照线虫特征图样进行鉴别.通过致病性实验研究线虫对肾茶生长的影响,并通过肾茶的长势、叶绿素、蛋白质含量等指标来评价.分离得到了海南肾茶的根结线虫,并成功进行了致病性实验.实验所用海南肾茶感染的线虫为南方根结线虫(Meloidyne incognita.).线虫严重影响肾茶的生长发育,使肾茶植株长势不良甚至死亡,重要代谢物质如蛋白质、叶绿素a含量明显下降.     

海南肾茶的组织培养快速繁殖

研究肾茶组织培养快繁的最佳材料、最佳激素配比、最佳培养基及炼苗移栽技术,以满足产业化生产肾茶对种苗的需求.以海南产肾荼幼嫩茎段的茎尖、茎节、茎间、叶片等为外植体,以MS为基本培养基,比较不同浓度和不同种类的生长激素对不定芽的萌发、愈伤组织增殖及丛生芽生根的影响.得出外植体消毒方法可采用70%的乙醇和0.1%的HgCI:溶液分时段来进行;最佳材料是茎尖;适宜的诱导培养基为MS+NAA 0.1 mg/L+6-BA 1.0 mg/L,继代增殖培养基为MS+NAA 0.5 mg/L+6.BA 1.0 mg/L或2,4-D 0.5 mg/L+6-BA 1.0 mg/L,生根培养基为1/2MS+CM10%+NAA 0.1 me/L;成功建立了海南肾荼组织培养快繁技术体系,掌握了炼苗和移栽的相关技术.     

鸡分腐解过程腐殖质络合态铜的变化及其淋溶特征

Chicken manure was composted for 110 d to evaluate changes in organic carbon (C) and humic substance-complexed copper (HS-Cu) extracted with water, sodium hydroxide (NaOH), and sodium pyrophosphate and sodium hydroxide mixture (Na₄P₂O₇-NaOH). The average HS-Cu content from the Na₄P₂O₇-NaOH extraction accounted for 46.8% of the total Cu in the compost, followed by those from the NaOH and water extractions, which accounted for 34.5% and 6% of the total Cu in the compost, respectively. NaOH-Na₄P₂O₇-extractable HS-Cu increased throughout the composting process. NaOH-extractable HS-Cu increased during the first 50 d of composting and then leveled off. Water-extractable HS-Cu enhanced during the first 21 d and then decreased. Water-extractable HS-Cu was not correlated to NaOH-or NaOH-Na₄P₂O₇-extractable organic C. The average amount of Cu leached from the compost was about 20% of the total Cu in the chicken manure and Cu leaching increased during the first 35 d of composting and then decreased. Leaching of Cu was significantly correlated to the concentrations of HS-Cu extracted with NaOH and water, but was not correlated to the concentration of HS-Cu extracted with NaOH-Na₄P₂O₇. Thus, NaOH-and water-extractable HS-Cu were relatively labile and NaOH-Na₄P₂O₇-extractable HS-Cu was relatively immobile. Composting process after rapid decomposition could result in low potential of Cu leaching because of formation of more NaOH-Na₄P₂O₇-extractable HS-Cu.     

局部水分胁迫对玉米根系生长的影响

采用分根法进行玉米水培试验, 研究局部水分胁迫对玉米根系生长的影响。设4个水分胁迫水平: CK, 0.2 MPa, 0.4 MPa, 0.6 MPa, 在整个根系经受一定的水分胁迫之后对部分根系复水处理, 测定局部供应后 0 h、6 h、12 h、1 d、3 d、5 d、7 d、9 d等不同时期各部分根系的面积、长度及干重。结果表明, 各胁迫程度均表现为, 与对照相比, 复水侧根区的根系面积、根长与根干重出现了明显增长, 且始终显著大于持续胁迫侧根区, 且随处理时间延长更加明显。不同胁迫程度下复水侧玉米根系的增长幅度不同。水分胁迫预处理后, 0.2 MPa水平下, 复水侧根区根系的面积、长度与干重以及整个根区总根长、总面积均可以达到甚至高于对照水平, 其他处理均显著低于对照。轻度胁迫后复水的根区根系产生明显的补偿效应。适度胁迫后复水有利于作物根系总面积增长, 但对总根长、根干重无显著影响。根系补偿效应与胁迫强度及复水的时间有关。     

磷对小麦旗叶氮代谢有关酶活性和籽粒蛋白质含量的影响

选用中筋品种鲁麦22和强筋品种济南17在大田条件下研究了不同磷素水平（P₀,不施磷;P₁,每公顷施P₂O₅ 105 kg;P₂,每公顷施P₂O₅ 210 kg）对小麦旗叶氮代谢有关酶活性、籽粒蛋白质积累和蛋白质组分含量的影响。结果表明,磷提高了灌浆前期和中期小麦旗叶硝酸还原酶（NR）和谷氨酰胺合成酶（GS）的活性,以及灌浆中期旗叶内肽酶（EP）的活性,其中对济南17的促进作用大于鲁麦22,而同一品种的P₁和P₂之间无显著差异;施磷亦提高了开花后14 d之前旗叶可溶性蛋白质含量和7 d之前游离氨基酸含量,与P₀相比,P₁有利于旗叶灌浆前期游离氨基酸的积累以及灌浆期间向籽粒的再分配,而过高的磷素水平（P₂）对于灌浆后期旗叶游离氨基酸向籽粒再分配的影响较小;磷对籽粒蛋白质合成积累的促进作用在灌浆前期较大,后期较小,表现为前期施磷处理籽粒蛋白质含量显著高于P₀,随着灌浆进程,差异逐渐缩小,最终2个品种P₁处理成熟籽粒中蛋白质含量最高;不同磷素水平对2个小麦品种蛋白质组分的影响不一,对于2个小麦品种籽粒中清蛋白和球蛋白含量之和P₁与P₀无显著差异,而P₁水平下籽粒谷蛋白和醇溶蛋白含量显著在鲁麦22中提高,在济南17中提高幅度较小,说明P₁水平对改善小麦的营养品质意义不大,但能够改善其加工品质;P₂水平下,济南17的加工品质有变劣的趋势。磷对小麦籽粒蛋白质各组分含量影响的复杂性要求在生产中,应针对不同品质类型小麦品种制定不同的优化栽培措施。