Performance of pearl millet isonuclear hybrids involving different cytoplasmic male-sterility systems

The performance of pearl millet hybrids involving four sources of cytoplasmic male sterility (CMS), including the most-exploited A₁ source, was compared to evaluate the effects of cytoplasm on grain yield. The mean grain yield of hybrids possessing A₂, A₃ and A₄ cytoplasms was either similar to or significantly higher than that of their counterpart hybrids with A₁ cytoplasm. Hybrids based on A₃ and A₄ cytoplasms produced, on average, 8% more grain compared with those based on A₁ cytoplasm. This suggested that these CMS sources could be used as alternatives to A₁ cytoplasm to widen the cytoplasmic base of hybrids. The results indicated that most of the variation in hybrids was accounted for by pollinator and cytoplasm × pollinator interactions, suggesting the use of genetically diverse pollinators in pearl millet hybrid breeding.     

Gamma Ray-Induced Field Tolerance to Phytophthora Blight in Sesame

Due to the non-availability of sources of resistance in Sri Lanka to Phytopbthora blight in sesame (Sesamum indicum) caused by Phytopbthora nicotianae var. parasitica, a mutation breeding programme was initiated. Seeds of three genotypes were subjected to six doses of gamma rays from 100 Gy to 750 Gy from a ⁶⁰Co source. Seeds of M₂ bulks, sampled by variety and treatment from the first five capsules formed on M₁ plants, were grown in a field with a history of repeated incidence of the disease. The best 21 lines, having the highest survival and seed production, identified in the screening of M₃ and M₄ progeny rows of selected M₂ single plants were then tested in a replicated field trial with the recommended cultivar ‘MI 3’ as a control. The plant survival in selected lines averaged 43.3 percent as against 7.2 percent in the recommended variety. Eight selections recorded significantly higher seed yield than ‘MI 3’ at P < 0.01 and another three at P < 0.05. Gamma ray treatments of 450 Gy and 600 Gy produced more lines tolerant to the disease than the other doses used.     

稻壳粉一次性筷子制备的试验研究

以稻壳粉为基材,以羧甲基纤维素钠和黄原胶为黏合剂、色拉油为脱模剂,利用正交试验找出最佳比例的配方。结果表明,最佳比例的配方为稻壳粉154.7 g,羧甲基纤维素钠7.65 g,黄原胶7.65 g,检测证明一次性可降解的稻壳粉筷子综合性能良好。     

Fertility restoration of new CMS sources in sunflower (Helianthus annum L.)

The development of commercial sunflower hybrids based on new CMS sources is of special interest for reducing the potential risk of vulnerability to pathogens and for increasing genetic diversity. From 263 test crosses involving nine new CMS sources, i.e. ANL1, ANL2, MAX1, PEF1, PET2, ANN1, ANN2, ANNS and ANN4, five lines were selected as potential restorers for PEF1, PET2 and ANN4. In test crosses between all nine CMS sources and these five restorer lines evaluated in 2 years, seven fully restored hybrids could be identified. These hybrids, based on ANL1, ANL2, MAX1, PEF1, PET2, and ANN4, showed good agronomic performance for plant height, days to flowering, maturity and oil content. Segregation analyses of the F2 populations indicate that a single dominant restorer gene was sufficient to restore pollen production of hybrids based on ANL2, PEF1 and PET2. For restoration of ANN4, two dominant complementary genes are required. In restoration of fertility in the crosses of ANL1 and MAX1 investigated, two dominant genes are involved each of which on its own allows the production of fertile plants.     

Heterosis and Genetic Variances and their Implications for Breeding Improved Varieties of Spring Beans (Vicia faba L.)*

Handcrosses were made in a factorial manner with 24 Vicia faba inbred lines m three sets, each between four male and four female parents. The resulting 48 hybrids, their parental inbreds and three commercial varieties were grown in performance trials during the years 1985—87 with three replications at one location. Yield and yield components were recorded on single plant basis. The average superiority of the hybrids above the control varieties was 26 % in plant yield. The best crosses outyielded the controls by more than 50 %. However, a few inbred lines also reached, the yield level of the controls. The average heterosis was significant for all characters except for maturity date. In plant yield the average heterosis was 75%, ranging between 34% and 148% in the various cross combinations. The highest average heterosis of 110 % was observed in yield at the lateral stems. In all characters the best inbreds were superior to the lower hybrids and in some characters even equal to the average of the hybrids. A strong positive relationship was found for all characters between hybrid performance and mid-parent value and between the per se performance of the inbreds and their general combining ability. Genotypic differences between the hybrids as well as between the inbreds were highly significant. Most of the variability between the hybrids in all characters were attributed to general combining, ability with only little evidence for specific combining ability. In the discussion the results are evaluated according to the choice of the breeding category of the partial allogamous faba bean species.     

基于虚拟仪器技术的风机性能自动测试系统

针对我国风机性能检测多以手工为主，存在试验手段落后，劳动量大和测试结果不准确等缺点，采用先进的虚拟仪器技术，将传感器技术、计算机技术和测试技术结合起来，建立了基于虚拟仪器技术的风机性能自动测试系统，实现了试验数据的自动采集、风机转速的自动调节、风机运行工况的自动控制、试验数据的正确处理及性能曲线的自动绘制。整个系统具有界面友好、操作方便、功能齐全等优点。试验结果表明本系统增加了试验过程的稳定性，避免了人为的读数误差、计算误差以及相关数据不能同时记录所引起的试验结果偏差，提高了测试精度和试验效率。可广泛应用于科研院所和风机生产厂家，具有较高的推广应用价值。     

农用车底盘偏置转向轴驱动轮运动与动力特性试验

为研究农用柔性底盘偏置转向轴驱动轮的运动与动力特性,设计了基于偏置转向结构的实验台。该实验台是一种水平转盘式的电动驱动轮性能测试试验台,且转盘的回转轴与偏置转向轴同轴,通过对电动轮及其车叉的试验分析来获取驱动轮的动力与运动参数。利用MATLAB/SIMULINK建立试验台模型并模拟了试验过程;试制了试验台并应用Visual Basic开发了试验台记录软件。在额定转速下进行了不同加载量的性能试验并与模拟结果进行了比较。试验结果表明:加载不同载荷时,电动轮达到稳定转速平均时间稳定为0.667 s;承载载荷500 N时的转向力为77.24 N,且偏置轴转向力与载荷呈线性关系,验证了实验台的可行性及模型的有效性。该研究可为偏置转向轴驱动轮的转向及参数优化提供参考。     

采用PLS-DA分析毛火方式对工夫红茶品质的影响

为探究不同毛火方式对工夫红茶品质的影响,明确新型电磁内热式滚筒-热风耦合干燥设备的毛火效果,该研究以一芽一二叶初展嫩度的"福鼎大白"品种为原料进行工夫红茶加工,设定电磁滚筒-热风耦合(Rotary pot-Hot air coupling First-Drying with electromagnetic heat,RHFD)、链板热风(Chain plate Hot air First-Drying,CHFD)、箱式热风(Box Hot air First-Drying,BHFD)、滚筒式滚炒(Rotary pot First-Drying,RFD)等4种毛火方式,比较所制茶样的茶多酚、儿茶素、茶色素、可溶性糖、咖啡碱、氨基酸等29个非挥发性指标,114个气相色谱-质谱技术(GasChromatography-Mass Spectrometry,GC-MS)检测的挥发性香气指标,10个外形和汤色色泽客观评价指标,同时进行了毛火方式的热效率、生产效率、生产成本等性能指标的分析比较,通过偏最小二乘判别统计(PartialLeastSquaresDiscriminationAnalysis,PLS-DA)分析毛火方式对优质工夫红茶品质的影响,并获得标志性差异化合物。结果表明:电磁内热式滚筒-热风耦合毛火处理下茶多酚和儿茶素总量显著最低(P<0.05),简单儿茶素含量较高,茶红素和可溶性糖含量、茶黄素综合指标TDE和茶色素综合指标10TFRB最高(P<0.05),毛火方式对茶黄素总量影响不显著(P>0.05);挥发性化合物总量以RHFD方式最高,RFD方式次之,CHFD方式最低;RHFD毛火方式芳香类、萜烯类等化合物含量最高。电磁内热式滚筒-热风耦合毛火升温快、温度分布均匀且稳定性好,热效率和生产效率高(分别为50.0%、220 kg/h),生产成本较低(仅0.32元/kg),预热时间仅14min;所制红茶在汤色透亮度、香气甜久度、滋味甜醇度等方面均得到提升,感官总分最高(P<0.05),达88.1。PLS-DA分析从挥发性和非挥发性角度均可将工夫红茶4种毛火方式显著区分,并分别获得了43种和18种差异化合物,结合差异性分析获得标志性差异化合物,2,4,6-三(1,1-二甲基乙基)-4-甲基环己-2,5-二烯-1-酮、香叶醇、3-辛酮、水杨酸甲酯、茶黄素、茶褐素、可溶性糖、表儿茶素等,可作为区分工夫红茶毛火方式,以及定向加工甜香、甜醇、高亮等优质工夫红茶的指标物质。该研究为红茶加工基础和品质提升提供技术参考和理论指导。     

秸秆覆盖畦田灌溉水流特性及灌水质量分析

在陕西杨凌张家岗村覆盖玉米秸秆的冬小麦地进行了畦田规格和灌水技术要素对灌水效率和灌溉均匀度影响的田间试验,并SRFR406软件对秸秆覆盖畦灌的水流推进进行了数学模拟.结果表明,给出的地面灌溉模型及软件可较好的模拟秸秆覆盖畦田水流运动.畦田规格与技术要素的选择对灌水效率及灌水均匀度均有影响.在覆盖秸秆畦田以畦长小于50 m,畦宽2～3 m,单宽流量以6～8 L/(m·s),坡度以3‰～5‰为宜.为提高秸秆覆盖灌水效率,应加强耕作管理,消除反坡.