毛叶秋海棠的杂交遗传特性

 采用毛叶秋海棠与云南野生秋海棠, 以及国外毛叶秋海棠的园艺品种进行正反交试验, 观测各杂交F1 代群体叶片斑纹、茎的类型、植株抗寒能力等主要性状的表现及其遗传特性; 通过F1 代自交, 对F2 代群体叶片斑纹的观测统计, 研究银绿斑性状的分离规律。试验结果表明: 毛叶秋海棠银绿斑与无斑是一对相对性状, 银绿斑对无斑是显性, 无斑对银绿斑是隐性, 其遗传杂交符合孟德尔的分离规律; B . rex ×B . longialata F1 代植株银绿斑性状的持续表现受光照强度的影响较大, 生长2 年后需要增加约2000 lx 的光照才能保持原有的银绿斑色彩; 毛叶秋海棠根状茎性状的遗传特性极为稳定, 遗传保持率90 %; 杂交F1 代在抗寒性方面表现了明显的杂种优势。     

陆地棉种内杂种F_2不同叶型生产力的研究

研究了3个正常叶型材料与鸡脚叶型材料杂交得到的杂种2代结果表明,选用适当亲本组配的杂交组合,不仅F_1能获得高产,F_2也有一定利用价值,其中尤以鄂棉15×鸡-2最好。对几个农艺性状与产量的相关分析表明,在条裂叶型、正常叶型材料中,果枝数、果节数与皮棉产量达显著正相关,条裂叶型F_2的纤维长度高于正常叶型。以合理正常叶植株与条裂叶植株的比例和适当的栽培措施改善农艺性状,便能提高F_2的产量和纤维品质。     

Physiological Performance of Wheat (Triticum aestivum dwarf.) Under Irrigated Situation

The objective was to study the behaviour of 20 dwarf wheats in a field trial under irrigated situation and also to suggest parameters or group of parameters conducive to high yield. Considerable variability existed in respect of tillering and earing, LAI, net photosynthetic rate, total dry matter production rate (TDMPR), harvest index, number of grains per main and subsidiary ears and grain size (1000 grain weight). Number of grains per main and subsidiary ears, total grains per plant, rate of net photosynthesis, leaf area and harvest index as well as total dry matter production rates were found to be positively correlated with grain yield and as such contributed maximum towards grain yield.
Thus, in general, it may be concluded that there should be minimum reduction in grain numbers between the main ear and the subsidiary ears, for this seems to be the one of causes of reduction in grain yield. Besides, there ought to be high ratio between net photosynthetic rate and dark respiration because large amount of dry matter is otherwise lost through respiration and many not be available for grains. High harvest index and high biological yield are also desirable characters which may be combined to obtain higher yields in wheats.     

Yield losses in soybeans from frogeye leaf spot caused by Cercospora sojina

Three soybean [Glycine max (L.) Merr.]cultivars (Samsoy 1, TGx 1025-12E and TGx 996-26E) were evaluated for yield losses resulting from frogeye leaf spot caused by Cercospora sojina Hara. Replicated field plots were established at two locations in Nigeria that have a high natural infestation of C. sojina. The cultivars were either not sprayed, sprayed once or sprayed twice during the growing season with the fungicide benomyl. Disease spread early in the season was from border rows of a susceptible soybean cultivar into the plots. Mean disease severity (DS) for unsprayed cultivars ranged from 0.6 to 4.5 on a scale of 0–5. Plots receiving two sprays had lower DS values, ranging from 0.5 to 2.4. Differences between unsprayed and double-sprayed plots for yield and 300-seed weight ranged from 2.5 to 58.8 and 0.6 to 28.6%, respectively. Seed weight was negatively correlated with DS.     

杜仲优良无性系幼龄期生长的相关性分析

本文对杜仲优良无性系前６年树高、胸径、产皮量、产叶量与树龄的相关关系进行了调查分析。结果表明，各无性系前６年树高、胸径生长的相关性均达到极显著水平。产皮量、产叶量与树龄呈非线性关系，相关指数接近１，产皮量、产叶量与树龄的相关关系密切，分析结果为杜仲优良无性系的早期选择提供了理论依据     

Effects of Soil Drought in the Generative Phase of Development of Field Bean (Vicia faba L. var. minor) on Leaf Water Status, Photosynthesis Rate and Biomass Growth

The effects of 10-day periods of soil drought during flowering (DI) or pod growth (DII) and during both these phases (DI + DII) on leaf water status, photosynthesis rate, plant growth and production of biomass was studied in pot experiments with field bean. Soil water content during drought spells were kept at 30% of field water capacity. Soil water deficiency DI and DII depressed the leaf water potential relatively to control by about 100 % and 140 % respectively, increased the water deficit by 100 % and 120 % and reduced photosynthesis rate by 80 % and 90 %. Rehydration of tissues completely abolished any decline of photosynthesis rate caused by drought DI, but after drought DII photosynthesis rate remained depressed by about 30 % even after rehydration. Drought periods DI and DII caused more rapid withering of leaves, a decline in the total leaf area and a temporary increase of root weight.
Drought occuring at flowering (DI) also activated the mechanism of plant adaptation to water deficiency during the pod formation phase (DII). Single or double periods of drought had not any significant influence on the number of pods and seeds, but decreased their weight.     

甜樱桃品种吉列玛叶片再生不定梢的研究

在基本培养基NN69或WPM上附加BA和低浓度的NAA，IAA，IBA作培养基，诱导甜樱桃品种吉列玛试管苗的叶片产生了不定梢。以WPM附加BA 3mg/L和IAA0．3mg/L的处理，不定梢再生率最高为33．3％。     

冷冬对美洲斑潜蝇越冬及发生趋势的影响

研究表明：在冷冬条件下，美洲斑潜蝇仍可安全越冬，但其在春季的发生推迟。冷冬对美洲斑潜蝇夏秋季发生趋势无影响。入梅的早迟，雨量的大小，雨日的多少，作物布局及长势，栽培方法等，是影响其夏秋季发生为害的主要因子，可在测报与防治上加以应用。