PREDICTIVE INTELLIGENT CONTROL OF THE COLD STORAGE

The predictive intelligent control scheme is proposed, which is based on approximation theory and numerical method of Chcbyshev orthogonal polynomial. It has the practical value to the cold storge using widely electromagnetic valve and can be also applied similar systems in orther area.     

Inheritance of plant elongation ability at seedling stage in rice

Summary In a comparison of methods to study inheritance of plant elongation ability, 15-, 20-, 25-, 30-, and 35-day-old F₂ populations of a cross between Baisbish (floating variety) and IR42 (nonelongating semidwarf modern variety) of rice, (Oryza sativa L.) were subjected to 65 cm water depth for 7 days. Frequency distribution of plant height before and after submergence was obtained. Bimodal curves in 15-, 20- and 25-day-old populations gave good fits to 9:7 elongating: nonelongating plants, suggesting that elongation was due to two dominant complementary genes. Segregation in the 30-day-old population was not clear-cut. A seedling age of 20 days was subsequently chosen for further studies.Two F₂'s involving floating rice and a nonelongating semidwarf; four F₂'s involving floating rice and an elongating semidwarf; and two F₂'s involving elongating and nonelongating semidwarf parents were studied with 20-day-old seedlings in the same way. Floating rice combinations with nonelongating semidwarf parents as well as with elongating semidwarf parents segregated into 9:7 elongating: nonelongating ratio. It is possible that because elongating and nonelongating dwarf parents did not differ much in elongation ability at seedling age, their combination with floating rice parents provided similar segregation. The F₂ distributions for height in elongating and nonelongating dwarf cross combinations were continuous with one peak.Genetic constitution of parents proposed are Sd1 Sd1 El El for floating parents, sd1 sd1 El El for semidwarf elongating, and sd1 sd1 el el for dwarf nonelongating.     

Prediction of the Line Value of a Genotype from a Top Cross with a Single Cross Hybrid

With the assumption of biallelism it is shown that differences in line values of genotypes from a random mating population can be predicted by the differences of values in top cross progenies with a heterozygous tester. This prediction is also valid in the case of multiallelism with a constant degree of dominance for each pair of alleles and if the tester is heterozygous for the more “distant” alleles. With an arbitrary tester, the efficiency of the prediction is affected by the proportion of the loci which are heterozygous for the more distant alleles. However, with the assumptions considered on multiallelism, with partial to complete dominance, the correlation between line value and combining ability with the tester is expected to be high for a large range of the repartition ot the loci. A two tester top cross design using highly complementary lines, could also be used.     

Inheritance of characters determining growth and development of tomato (Lycopersicon esculentum Mill.) under low energy conditions

Summary Diallel crosses were made between 15 tomato genotypes with varying performance under a low energy regime. It appeared that differences between genotypes for 11 vegetative and generative plant characters are determined mainly by additive genetic variation. For breeding cultivars adapted to low energy conditions, crossing genotypes with a high GCA for weight of trusses and fruits (WTF) and genotypes with a high GCA for weight of vegetative plant parts (WVP) seems most promising. Complications may arise from the negative correlation between GCA values for WTF and WVP, and the strong positive correlation between GCA values for fruit number and WTF, causing small fruits.     

Mass selection for kernel depth in early maize

Summary Effectiveness of mass selection for kernel depth in an early maize (Zea mays L.) synthetic, i.e. NDSAB, was evaluated in eight North Dakato environments. Four cycles of selection for deeper kernels were evaluated for grain yield and associated traits by using corresponding randomly selected subpopulations of NDSAB to adjust out inbreeding effects on selected subpopulations. General combining ability (GCA) effects of selected subpopulations also were evaluated for these traits.Subpopulations selected from one to four cycles for deep kernels were reciprocally crossed to corresponding randomly selected subpopulations in a factorial mating design. Subpopulations, selfed subpopulations, and subpopulation crosses were evaluated for yield and associated traits. Subpopulations selected for deep kernels generally had deeper kernels, higher yields, heavier kernels, more kernel rows per ear, and lower test weights than corresponding randomly selected subpopulations. Differences in GCA effects among selected and unselected subpopulations generally corresponded to differences between selected and unselected parental subpopulations. Inbreeding effects from selfing were observed for all traits, but no average heterosis was detected when subpopulation crosses were compared to parental subpopulations. Reciprocal differences were observed for all traits except kernel depth, but these differences were inconsistent relative to whether deep kerneled females made superior hybrids to unselected females.Results supported the use of mass selection for kernel depth as a means of grain yield improvement in the short term for NDSAB. However, negative associations of kernel depth with test weight may restrict long term use of this procedure.Journal Article No. 1505 of the North Dakota Agric. Exp. Stn., Fargo     

大豆亲本品种数量性状的配合力分析

采用6个大豆亲本双列杂交设计,研究亲本及F_1、F_2的配合力.各性状的一般和特殊配合力方差分析多达显著水平.一般配合力效应表现较好的有豫豆6号和郑8431.在F_1和F_2中同一性状不同组合或同一组合不同性状间的特殊配合力效应具有显著差异.在不同世代中根据遗传力的大小,应对不同性状进行选择.单株粒重遗传力较低,不易在早期世代选择.     

小麦白粒种质资源抗穗发芽性的配合力分析

用我国抗穗发芽性显著不同的21个白粒小麦品种(系)及1个红皮品系为材料,分别配成5×6、4×7和7×5三套NCⅡ交配设计,以穗发芽率为指标对杂种F_1及亲本进行配合力分析。结果一般配合力方差达极显著水平,特殊配合力方差亦显著或极显著,基因加性效应起主要作用。抗性亲本对杂种抗穗发芽性表现的作用显著大于敏感亲本,其平均穗发芽率与其一般配合力效应间相关较高,平均相关系数为0.816。穗发芽抗性遗传力较高,广义遗传力和狭义遗传力平均分别为83.30％和58.96％,可以在杂种早代-中代对其进行选择。涪陵须须麦、万县白麦子、遂宁坨坨麦、万雅M120E6、丰产3号等具有较好的一般配合力,可作为优良白粒抗源在育种中利用。     

Combining ability for rancidity and associated traits in pearl millet (Pennisetum glaucum)

Pearl millet occupies an important place in attaining nutritional security in marginal areas; however, as it develops off-flavours, it is less preferred by food industry. The objective of the current study was to determine the variations in rancidity-related traits and estimate the combining ability of inbreds and hybrids for these traits under varied environmental conditions. In this study, 32 hybrids were developed from eight lines and four testers using line × tester mating design and evaluated along with parents and checks 86M86 and HHB 67 for yield and rancidity-associated traits in three environments. The hybrids L7T2 and L6T1 are identified as promising hybrids for grain yield and rancidity. Higher variance due to specific combining ability and predictability ratio for grain yield and rancidity-associated characters indicate the predominance of non-additive gene action. The tester T1 recorded a significant negative GCA effect with low alcoholic acidity. A significant and positive SCA for grain yield was observed in L3T1 and L7T2, whereas for rancidity in L5T4. Alcoholic acidity showed a significant positive association with 1000 seed weight, lipase and lipoxygenase in parents and negative association with 1000 seed weight in hybrids.     

食源性致病菌单细胞观测与预测的研究进展

微生物在单细胞水平下的生长普遍具有随机性和变异性,同时低菌量污染食品所造成的危害风险亦不可忽视,因此食源性致病菌单细胞的生长观测及预测研究逐渐成为食品预测微生物学及食源性致病菌风险评估的研究热点。在分析现有相关文献的基础上,将目前主要的食源性致病菌单细胞生长观测研究分为间接推断和直接观测两类方法;同时对食源性致病菌单细胞生长预测的模型参数与建模过程进行概述,比较了传统预测微生物的决定模型与微生物单细胞的随机模型二者之间的区别,强调了单细胞生长模型需在随机建模的基础上开展,并通过个体建模方法进一步联系其与所在食品环境之间的关系。最后,分析了食源性致病菌单细胞生长观测与预测的现状,并展望了其未来与食品安全风险评估相结合的发展趋势。     

创新教学方法培养创新人才

培养具有创新能力的优秀人才是对高等教育的本质要求：学生创新能力的培养具有多种方式，其中，创新教学方法是培养创新人才的一种有效途径。我们在农业工程类专业课程教学中，积极进行教学方法的创新，鼓励学生进行自主性教学活动，提高了学生的创新能力，收到了很好效果。