桂糖21号等甘蔗新品种的茎尖脱毒培养技术

采用52℃热水处理+38℃热处理+茎尖脱毒+工厂育苗技术培育桂糖21号、桂糖26号健康种苗,保持自育良种的品质。热处理期水分影响蔗茎的萌芽率,桂糖26号热处理10 d萌芽率达90%,出芽较桂糖21号稍快而且整齐。新台糖16号、22号剥取的茎尖稍大(<1 mm),茎尖成活率达80%,接种前期转管周期4-7 d,能有效减轻酚害。     

冬植小果型番茄新品种引种试验初报

对9个小果型番茄新品种的引种比较试验结果表明:综合性状最好的品种是台湾亚蔬11号,其次是甲天下11,再次是龙女,均表现为丰产,较早熟、耐热、极耐寒、抗病毒病、高抗疫病;且畸形裂果率低,商品果颜色大红、光泽度高、果形均匀端正,美观,果实紧实、坚硬适合长途运输、适宜外销或出口,具有极强的市场竞争力,可作为当家品种在当地生产推广。     

不同水稻品种间栽方式控制稻瘟病试验

利用4个当地主栽杂交稻品种与1个优质感病糯稻品种配置4个组合进行混合间栽组合控制稻瘟病试验。结果表明,不同品种混合间栽对稻瘟病具有较好的防治效果,间栽区各品种的平均叶瘟和穗瘟发病率均比净栽区低,尤其对优质易感病糯稻品种,穗瘟相对防治效果达到46.90%~77.36%。混合间栽较之净栽区可在一定程度上增加各品种的单位面积产量,平均增产幅度可达675.0~921.3 kg/hm2。     

玉米品种的耐瘠性研究

选取贵州地区广泛种植的具有较好耐瘠高产特性的12个玉米品种,利用在中低肥力土上筛选出耐瘠性强的品种和在高肥力土上展现出较高的产量空间的方法,采取与生产相近的条件,筛选出了适合黔中地区推广的耐瘠优质的玉米品种遵玉8号、农大108和黔单16号等.利用耐瘠与不耐瘠玉米在主要性状上的对比鉴定,找出了与玉米耐瘠相关的根数、根系体积、根重和地上部鲜重等几个指标,为耐瘠玉米的评价建立了一定的基础.     

Effect of rice variety on methane emission from an Indonesian paddy field

Variations in CH₄ emission from a Sumatra paddy field in which 8 popular modern varieties in Indonesia were grown were compared in the 1994/1995 rainy season. Total amounts of CH₄ emitted during the period of rice growth were in the ranges of 32.6-41.7 and 51.3–64.6 g CH₄ m^-2 for the plots amended with chemical fertilizer only and those amended with both rice straw and chemical fertilizer, respectively. The mean CH₄ emission rate was highest in the plot with the variety Bengawan solo and lowest in the plots with the varieties Atomita-4 and Way seputih among the plots which received chemical fertilizer, while highest in the plot with Way seputih and lowest in the plot with Bengawan solo among the plots amended with both rice straw and chemical fertilizer. The increase in the mean CH₄ emission rates by rice straw application was higher for the plots planted with Way seputih (1.98 times) and Atomita-4 (1.77 times) than for the plots with Bengawan solo (1.23 times) and IR-64 (1.35 times). The plots with Walanai and Cisanggarung recorded intermediate mean emission rates and the increase in CH₄ emission by rice straw application was also intermediate (1.57–1.64 times). It was noteworthy that Way seputih and Atomita-4 were derived from the variety Cisadane, Bengawan solo and IR-64 from the variety IR-54, and Walanai and Cisanggarung from the varieties IR-36 and Pelita 1-1, respectively.

The amounts of CH. emitted for 1 kg grain production ranged from 53 (Atomita-4) to 74 (Kapuas and Walanai) and from 89-93 (IR-64, Bengawan solo, and Atomita-4) to 121 (Kapuas) g CH₄ kg^-1 of grain for the plots amended with chemical fertilizer and those amended with rice straw and chemical fertilizer, respectively.     

Effect of nitrogen application during ripening period on photosynthesis and dry matter production and its impact on yield and yield components of semidwarf iniica rice varieties under water culture conditions

Abstract

A water culture pot experiment was conducted to analyze the effects of N application during the ripening period (RP) on photosynthesis, dry matter production, and its impact on grain ripening and yield in two semidwarf indica type varieties viz. Gui Zhao 2 (GZ) and BR3 (BR) compared with a japonica type variety Koganemasari (KO) under four N rates viz. 0 (N₀), 10 (N₁₀), 20 (N₂₀), and 40 (N₄₀) mg L^?1. Results showed that N application enabled to maintain a higher leaf area and delay leaf senescence in both indica and japonica type varieties but the decrease in the rate, of leaf area was higher in the former than in the latter and the rate was reduced with increasing N rates. Flag leaf photosynthesis and SPAD values of N treated plants were higher throughout the RP, showing the presence of a significant correlation either for each variety or all the varieties together. Higher photosynthetic rate was supported by higher leaf chlorophyll (SPAD value basis) content, stomatai conductance, and N concentration in leaf blades. Top dry matter content increased with increasing N rates mainly due to mean leaf area rather than NAR except for BR during RP but it was higher in KO than in GZ and BR. Reduction of shoot weight due to translocation of dry matter to panicles during RP was suppressed by N rates both in GZ and BR while shoot weight increased in the N-treated plants in KO. The dependency of KO on current photosynthates for panicle weight was found to be almost hundred percent while the contribution of stored carbohydrates in shoot before heading to panicle weight in GZ and BR was in the range of 4-27 and 33-54%, respectively and the rest was contributed by current photosynthates. The percentage increased with increasing N rates. Percentage of ripened grains (PRG) increased with increasing N rates in GZ and BR due to the increase in dry matter production and in the photosynthetic rates of apex leaves, despite the larger spikelet number and larger hull size. However, KO showed almost no variation although it had the highest PRG among the varieties. Brown rice yield followed the same pattern as that of PRG in GZ and BR and the highest yield was produced by BR followed by GZ and KO. These results suggest that N application during RP was more effective in increasing yield in the semidwarf indica type varieties than in the japonica type variety.     

不同品种小麦籽粒中戊聚糖含量分析

从全国小麦主产区收集弱筋小麦品种19份、强筋品种24份,对小麦籽粒中的戊聚糖含量以及籽粒基本品质特性进行了测定与统计分析。结果显示,不同类型与品种的小麦籽粒中总戊聚糖(TP)和水溶性戊聚糖(WSP)含量存在极显著差异（P<0.01）;强筋小麦的TP和水不溶性戊聚糖（WUP）平均值较弱筋小麦的偏高,但二者的WSP平均值基本一致。对籽粒的戊聚糖含量与其品质特性进行相关性分析发现,强筋小麦籽粒的WSP含量与籽粒蛋白质含量、湿面筋含量、zel沉降值、面团稳定时间存在正相关关系;弱筋小麦籽粒WSP含量与籽粒蛋白质含量、湿面筋含量、硬度、zel沉降值、形成时间存在负相关关系。通径分析结果显示,蛋白质与湿面筋含量对戊聚糖含量的影响更为显著。由本研究得出结论,强筋与弱筋类型小麦的品质指标对戊聚糖含量的影响有明显不同,建议未来戊聚糖的研究按小麦类型区别对待。     

多对象特征提取和优化神经网络的玉米种子品种识别

为了实现机器视觉代替人的视觉,对玉米种子品种进行实时、客观、准确和无损伤识别,研制了玉米品种识别硬件系统和软件系统。针对玉米种子及种子图像的特点,对玉米种子品种识别技术与算法进行了深入地研究和探索,提出了一种基于多对象有效特征提取和主成分分析优化神经网络的玉米种子品种识别方法,提取了玉米种子的几何特征和颜色特征参数,优化了基于机器视觉的玉米种子图像处理策略和品种识别算法,提高了玉米品种识别的速度和准确率。对农大108、鲁单981、郑单958、五岳18共4个品种玉米种子进行了品种识别试验,每粒种子识别的平均耗时为 0.127 s,综合识别率达到97%以上。研究表明,基于机器视觉的玉米种子品种识别与检测方法是可行的,该方法可提高玉米种子品种识别效率和正确率。     

低磷胁迫对不同基因型小麦品种苗期性状的影响

为研究低磷胁迫对小麦苗期性状的影响,在对照(200 μmol/L KH2PO4)和低磷(5 μmol/L KH2PO4)条件下比较了6个不同基因型小麦品种苗期性状指标。结果表明,小麦根系和地上部对低磷胁迫的反应不同,低磷诱导小麦根系伸长,根系生物量（根鲜重和根干重）增加,供试的6个小麦品种在低磷条件下的根系鲜重和干重与对照相比差异均达到显著或极显著水平。低磷处理对地上部则表现出抑制作用,但对不同品种的影响程度差异较大。总体来看,低磷胁迫处理对小麦根系性状的影响大于地上部性状,不同苗期性状受低磷胁迫影响的程度分别为：根系鲜重>最长根长>根系干重>地上部鲜重>地上部干重>苗长。6个供试小麦品种中,‘中国春’对低磷胁迫最为敏感,而‘京411’的耐低磷性相对较强。     

几种模型在玉米区域试验的适用性与品种评价中的差异研究

为了综合评价玉米区域试验的结果,采用Shukla模型、Finlay-Wilkinson模型、Eberhart-Russell模型和加性主效乘式互作模型(AMMI)等4种常用模型对中国5个类型的玉米品种区域试验资料进行了拟合与分析。结果表明,没有一个模型对所有试验资料的拟合效果都最佳,Finlay-Wilkinson模型对5个试验拟合效果均最差,AMMI模型对3个试验的数据拟合效果最佳,Shukla模型和Eberhart-Russell模型则分别对一个试验拟合效果最佳。各个模型在玉米品种产量差异显著性检验和稳定性排序等方面存在较大的差异。因此,在玉米区域试验的实际分析中应采用AMMI模型或者利用模型拟合信息量准则选用最佳的模型进行分析,以提高玉米区域试验对品种高产与稳产评价的准确性。