Mutant induction through adventitious buds of Kohleria

Summary Freshly cut leaves of Kohleria eriantha and K. x Longwood were exposed to a wide range of gamma irradiation doses and allowed to root and form adventitious buds. K. Eriantha could not be successfully propagated from leaf half cuttings. Longwood produced a small number of adventitious plantlets as compared to other Gesneriads. Colchicine treatments reduced leaf half survival in Longwood by more than 50%. Leaf halves exposed to low and moderate doses of gamma irradiation showed increased overall plantlet production compared to nonirradiated leaf halves.Of the mutation parameters calculated, the number of mutants per 100 surviving leaf halves appears to be the most useful since it relates the number of mutants within a dose to the number of surviving leaf halves, the number of mutants to the number of plants produced, and the number of mutants within doses to control values.Using the criteria, number of mutants per 100 surviving leaf halves, optimum production of all mutants, of useful and of dwarf mutants was obtained at 2.5 kR for noncolchicine treated leaf halves and 1.5 to 3.0 kR for colchicine treated leaf halves.Of the adventitious plantlets produced, 13.8% were classified as mutant types. Mutant plants were found in radiation dose levels up to 5.5 kR. The array of mutants produced was skewed toward plant habit and flower characteristic mutants with several leaf characteristic, lethal, and polyploid mutants observed. A high frequency of mutants, 10 of 93 plants, occurred in the nonirradiated controls. Four sectorial chimeras were identified from both control and irradiation exposed groups. Several potentially useful flower color and dwarf mutants have been selected for further study. Adventitious buds may have developed from callus at petiole and leaf-vein bases. Colchicine treatments severely inhibited adventitious plantlet production and because of this could not be used as a criterion to identify the origin of adventitious buds. Conclusive determination of the organogenesis of adventitious buds from Longwood leaf halves could not be made. Mutant plantlets formed from adventitious buds on detached leaf halves of Longwood appear to arise from single cells as has been found with other Gesneriads.Scientific Journal Series Article No. 10 330 of the Minnesota Agricultural Experiment Station.     

The Extended Kalman Filter Data Fusion Algorithm Based on Discrete Stationary Wavelet Transformation

It is difficult to establish precise mathematical model in extended Kalman filter data fusion algorithm for GPS/ DR integrated vehicle navigation system, an improved extended Kalman filter data fusion algorithm is put forward based on Discrete stationary wavelet transformation. The simulation results show that the algorithm is better than the extended Kalman filter data fusion algorithm, and is available for GPS/DR integrated vehicle navigation system.     

米糠油防治储粮害虫的研究

"米糠油防治储粮害虫研究"表明,毛米糠油是一种对储粮害虫有强引诱力的植物性诱杀剂,用毛米糠油防治储粮害虫,方法简便易行,成本低廉,不污染粮食,不影响粮食的加工和经济价值,不产生公害,特别是消除了害虫的抗药性.它不仅适用于大规模储粮的国库,亦适宜于城乡千家万户的小批量储粮.     

Crossability relationships of andean potato varieties of three ploidy levels

Summary The formation of triploids in 4x×2x crosses was studied in primitive potato varieties from the Andes of Peru and Bolivia. Triploid frequencies were as high as 80–100% in some crosses, although the actual number of seeds was low. The triploid block varied according to the tetraploid parent, and was never entirely absent. The likelihood of triploid formation was studied in 4x×2x crosses where pollen from both tetraploids and diploids of known genotype was used. Even though the diploids were chosen for their non-production of 2n gametes, as detected in pollen grain size, 66% of the hybrids were tetraploid. The amount and probability of gene-flow between the tetraploid and diploid gene-pools, either directly through 2n gametes or through triploid bridges was examined. Most of the 20 cultivars of S. x chaucha produced seed in crosses with tetraploids and diploids, although the fertility of the latter crosses was four times higher. The female fertility of some of the triploids thus allows them to exchange genes with the tetraploids and diploids, although gene-flow occurs more rapidly through direct transfer from diploids to tetraploids via 2n gametes.     

Comparison of pedigree selection and single seed descent for oil yield in linseed (Linum usitatissimum L.)

Summary Four populations of linseed derived from five parents were advanced from the F₂ to the F₆ generation by SSD and to the F₅ by pedigree selection. These populations were used to compare the efficiency of the two methods in order to provide superior genotypes with respect to grain yield and oil content, i.e. oil yield. The results showed minimum differences between pedigree and SSD lines for grain yield, where in only one cross the SSD lines were significantly superior to the pedigree lines. Since pedigree selection was carried out for both, seed yield and oil content, a positive response to selection was expected. However, early selection for yield, a character with low heritability, was not successful. On the contrary, significant differences for oil content were detected between the two groups of lines in three of the four crosses studied. In these cases the pedigree lines were superior to the SSD lines. These results demonstrate that strict selection in early generations for oil content, a character with comparatively high heritability, is feasible and successful in linseed. However, selection for seed yield should be postponed to later inbred generations. Consequently, in breeding for maximum oil yield of linseed a two-step selection procedure is recommended.Abbreviations PS pedigree selection - SSD single seed descent - TGW thousand grain weight     

冬小麦对不同土壤水分的生理和形态响应

采用深桶栽培结合测坑法，从冬小麦反青至蜡熟期保持不同的土壤水分，分生育期对小麦的形态、生理和根系进行了测定。结果表明：调控土壤水分可明显改变冬小麦根、冠生长量比率。适宜的土壤水分胁迫（田持的５０％－６０％）可促进冬小麦根系发育，高土壤水分更有利于地上部生长。土壤水分长期低于田间持水量的６０％时，较显著地叶片的增大，从而减小截获光能的总叶面积，最终降低生物学产量和经济产量。土壤水分由“田持”的４６％升高到５５％，光合速率增幅不大，由５５％提高到６４％，光合速率出现跃迁式增高，土壤水分超过６４％后，光合速率几乎为等值。说明光合作用对土壤水分存在一个“阈值”反应，此值为土壤田间持水量的６５％左右。冬小麦的蒸腾速率随土壤水分递增而一直递增；综合考虑蒸腾速率与光合速率及水分利用效率之间关系，可以得出高土壤水分条件下冬小麦存在奢侈蒸腾耗水现象。     

番木瓜植株镁钾含量变化与缺钾叶枯病的关系

采用田间调查、采样及其室内分析与田间试验相结合的方法,在低钾而高镁的土壤上,从植株各个部位探索番木瓜植株镁、钾营养变化对其生理性缺钾叶枯症的影响。结果表明,番木瓜叶枯症的发生,除与土壤有效钾缺乏有关外,Mg/K比值过高也是导致该症发生的一个重要原因。发生缺钾叶枯病的番木瓜植株,其根、茎、叶片、叶柄等器官含镁量均明显提高,施用钾肥后不但提高了植株的含K量,而且能抑制番木瓜植株对镁的吸收,从而协调平衡Mg/K比值,生理性缺钾叶枯症得到有效控制。     

百花山山地土壤中有机质的垂直分布规律

本文测定了北京百花山山地典型土壤剖面各发生层的有机质含量、腐殖酸组分、可见光谱,利用相关分析方法计算了有机质与海拔高度之间的相关系数。结果表明:有机质与海拔高度的相关系数为0.94,,呈显著相关水平;各剖面土壤腐殖质分析结果表明,该山地土壤的HA/FA值、E4/E6值随着海拔高度的升高而呈现上升趋势。     

高产香蕉平衡施肥技术研究

在肥力较高的老蕉园进行平衡施肥技术研究。结果表明:当第一造蕉氮肥用量达到1000kg/hm2以上及氮钾肥施肥比例N K2O为1 1 15时,香蕉抽蕾提前,蕉果农艺性状及品质较好,产量达到52 5t/hm2的高产水平,获得较好的经济效益;随着施钾比例的增加,香蕉的营养生长受到一定的限制,农艺性状及品质均变差,产量及经济效益均有所下降。在土壤Mg/K=1 37的情况下增施镁肥,香蕉的营养生长受到一定影响,蕉果的农艺性状下降,但固形物与可溶糖含量提高,产量及经济效益明显降低;施用硫肥对香蕉的生长及产量影响不大,但由于增加了肥料成本而使经济效益有所下降。