Ultrastructure and Lipase Activity of Cotyledon cell During Pod Development in Peanut

A series of significant changes of the ultrastructure and lipase activity of cotyledon cell were found in peanut (Arachis hypogaea) during pod development. In he initial stage of cotyledon development there were many plastids which kept producing starch grain and there were low lipase activity and very few lipid and protein bodies in the cell. In the middle stage of cotyledon development, a great number of larger lipid bodies were seen in the cell and a lot of protein bodies formed in the vacuoles and continued to increase in size. Lipase activity increased in the cytoplasm, endoplasmic reticulum, protein bodies, plasmalemma and intercellular space. In the later stage of cotyledon development, the lipid bodies did not increase in number but became slightly larger. The protein bodies continued to increase both in number and in size. Lipase acttvity was even hegher in the cytoplasm. In the final stage the protein bodies became irregular in shape and some of them tended to disintegrate with their content entered into the space around the lipid bodies. The lipase activity in the cell declined. The results indicated that the lipid body originated in the cytoplasm and the protein body originated in the vacuole; that the accumulation of oil and protein in peanut cotyledon resulted from the formation and development of lipid and protein bodies in the cell, and that the changes of plasmid and lipase activity in the cell played a role in the development of lipid body during the development of cotyledon.     

Paramural Bodies in Callus Beside the Isolation Layer of the Graft Union

The isolation layer of the graft union is a changeable component. It is formed and thickened during the early stage (Fig. 6) and disrupted, thinned and even disappeared durmg tile later stage of development of the graft (Fig. 1, 2, 14). A number of vesicles, paramarat bodies (Fig. 3, 5, 8, 9, 11, 13, 19), multivesicular bodies (Fig. 4, 15, 16, 18, 20) and concentric membrane bodies (Fig. 7) are observed in callus 'beside the isolation layer during both stages of development based on transmission electron microscopy. The paramural body comprises invagination of plasmalemma containing numerous vesicles and/or tubules situated between the cell wall and the plasmalemma. The multivesicular body is a organelle about 0.5-μm in diameter with a single membrane surrounding several smaller single vesicles. It is possible that multivesicular body and/or single iesicles transverse the plasmalemma to produce paramural body. The figures show that the paramural bodies appear always beside the isolalion layer at the different stages of development of the graft union and the multivesicular bodies appear mostly near the region where plasmodesmata are secondarily formed between the stock and the scion (Fig. 15, 17, 20). This may reflect that paramural body and multivesi- cular body, as well as single vesicles, are capable of performing vesicular transport. The deposition and reabsorption of material of the isolation layer occur due to vesicular transport. All the above facts seem to indicate that paramural body, multivesicular body and single vesicles can be both endocytotic and exocytotic. The present study supports the theory of vesicular transport, and authors suggest that transcellular cytosis occurs not only through plasmodesmata but also through plasmalemma in oapoplast. The single vesicles, paramural bodies and multivesicular bodies take an active part in the transport process of symplast-apoplast-symplast.     

Cyto-Chromosomal Analysis of Developing Wheat Monosomics

In order to achieve the aim of advanced breeding program with the definite direction, it is necessary for us to develop the monosomic lines used for the wheat breeding programs in China. We fixed the wheat ears at appropriate stage in Carnoy’s fluid, and stained with acetocarmine in every generation from the different crosses mentioned above. According to their karyotypes of metaphase 1, the monosomics, normal bodies, monotelosomics, ditelosomics and allotypic bivalents were identified (Plate Ⅰ, 1–8). In the process of developing monosomic lines “Beijing Red No.1”, some monosomic lines such as 5A’s and 4D’s, can be directly proved by their phenotypes, other lines of monosomic 1B, 5B add 6B can also be directly proved to be true by their typical chromosomal morphology. In order to check the accuracy of chromosomal orders of monosomic lines, we tested all 21 monosomic lines of “Beijing Red No.1” by means of telosomic testing. At the same time we tested the origirnal monosomics of “Chinese Spring” as a check. In the F1’s of test crosses, those showing 20 bivalents and one monoelemic (20”+t’) were proved to be right. Whereas those showing 19 bivalents, 1 univalent and 1 allotypic bivalent (19”+1’+1’t’) were proved to be wrong. The karyotypes of F1’s from the test crosses for “Beijing Red No.1” can be verified by compairing with that of the check. During some years, we have examined 500 F1 plants of test crosses for monosomic lines of “Beijing Red No.1”, and some what less plants for monosomic lines of “Chinese Spring”. The number of observed cells usually was 100–200, the least was 40 and the most was 600. As the result, all F1's of test crosses showed accurate karyotypes. Besides detemning the F1 karyotypes of test crosses, we also analysed and compared their phenotypes with each other (photograph 9–12). According to the pbenotypes caused by the chang in chromosome number, structure and gene dosage, not only we can check the accuracy of testing result, but also locate the genes controlling some characters on the chromosomes or chromosomal arms.     

The Protein Body in Dedifferentiating Cels of Tobacco Leaf Explants

Light and electron microscopic observations show that a kind of spherical electron-dense body appears in the dediffercntiating mesophyll cells and their subdivided cells in tobacco leaf explants cultured for more than two days. The larger electron-dense bodies (1.0–1.5μm in diameter) present in vacuoles while the smaller ones (0.1–0.8 m in diameter) in cytoplasm. This implies that the bodies first can be formed in cytoplasm and then secreted into vacuoles. Since the bodies can be fixed with glutaradehyde and 3H- leucine can incorporated into them, they may be recognized as protein bodies. The protein bodies usually closly combined with newly formed cytoplasmic masses so we suggest that they probably play some role in cytoplasmic growth of dedifferentiafing ceils.     

Foliar modifications induced by inhibition of polar transport of auxin

The effects of auxin polar transport inhibitors,9-hydroxy-fluorene-9-carboxylic acid (HFCA);2,3,5-triiodobenzoic acid(TIBA) and trans-cinnamic acid (CA) on leaf pattern formation were investigated with shoots formed from cultured leaf explants of tobacco and cultured pedicel explants of Orychophragmus violaceus,and the seedlings of tobacco and Brassica chinensis,Although the effective concentration varies with the inhibitors used,all of the inhibitors induced the formation of trumpet-shaped and/or fused leaves.The frequency of trumpet-shaped leaf formation was related to the concentration of inhibitors in the medium.Histological observation of tobacco seedlings showed that there was only one main vascular bundle and several minor vascular bundles in normal leaves of the control,but there were several vascular bundles of more or less the same size in the trumpet-shaped leaves of treated ones.These results indicated that auxin polar transport played an important role on bilateral symmetry of leaf growth.     

Spatiotemporal variation in selection on body size in the dung fly Sepsis cynipsea

Standardized measures of the strength of selection on a character allow quantitative comparisons across populations in time and space. Spatiotemporal variation in selection influences patterns of adaptation and the evolution of characters and must therefore be documented. For the dung-breeding fly Sepsis cynipsea, we document patterns of variation in sexual, fecundity and larval and adult viability selection on body size at several spatiotemporal scales: between-populations, over the season, over the day and between dung pats. Adult viability selection based on residual physiological survivorship in the laboratory was nil or weakly negative. In contrast, larval viability selection in two laboratory environments was weakly positive for males at low competition and females at high competition. Fecundity selection was positive and strong at all times and in all populations. Sexual selection reflecting pairing success was overall strongly positive (about three times stronger than fecundity selection), while selection reflecting male reproductive success via the clutch size of his mate (i.e. assortative mating) was essentially nil. Only sexual selection varied significantly at coarse (between populations and seasonally) but not at fine (within a day or between pats on a pasture) spatial and temporal scales. Quadratic and correlational selection differentials were low and inconsistent in all episodes except for fecundity selection, where there was some evidence that clutch size reaches an asymptote at large body sizes, implying weaker selection for large size as females get bigger. Implications of these results for the evolution of body size and body size dimorphism are discussed.     

Pheromonally mediated mate attraction by males of the burying beetle Nicrophorus orbicollis: alternative calling tactics conditional on both intrinsic and extrinsic factors

Male burying beetles attract females using a pheromonal signaland can provide parental care and a food resource, vertebratecarrion, for their developing offspring. But males attempt toattract females even when they have no carrion. We examinedthe factors that influence male behavior directed toward findingor attracting mates in both field-caught and laboratory-reared Nicrophorusorbicollis, a North American burying beetle. We investigatedwhether male behavior differed based on both intrinsic (size)and extrinsic (resources held) differences among males. Further,we examined repeatability of individual behaviors and the effectof holding or lacking resources on these repeatabilities. Field-caughtand laboratory-reared individuals differed in overall activitybut not in their behavioral repertoire, making studies of laboratory-rearedmales relevant. The behavior of individual males was very consistentwithin a condition, but plastic between resource conditions.The frequency of calling (adopting a posture that indicatespheromone release to attract females) depended on male sizewhen males did not hold resources, but this relationship disappearedwhen males held resources. Without carrion, smaller males calledmore frequently than did larger males. When holding carrion,smaller males reduced their calling, whereas larger males significantlyincreased the frequency with which they attempted to attractfemales and reduced the amount of time they spent searching.Thus, calling behavior of males was conditional on not only intrinsicand extrinsic factors, but also an interaction between them.We suggest that the changes in calling represent alternativetactics based on the costs and benefits of attracting both potentialmates and competitors, which differ for males of different sizes.     

长爪沙鼠寄生蚤指数和气象因子关系的研究

根据内蒙古自治区土默特平原1983～1985年长爪沙鼠 Meriones unguiculatus巢蚤、体蚤、洞干蚤指数和6项气象资料进行分析,得到如下结果。① 共获蚤11种, 其中秃病蚤蒙冀亚种Nosopsyllus laeviceps kuzenkovi(67.50%)是优势种, 二齿新蚤Neopsylla bidentatiformis(22.65%)为次优势种。② 3种蚤指数的均值差异显著(P<0.0001)。③ 体蚤与洞干蚤指数相关显著(P<0.05), 模型为(洞干蚤指数)=0.0049+0.0248(体蚤指数), 巢蚤与体蚤、巢蚤与洞干蚤指数的相关不显著(P>0.25)。④ 沙鼠密度与3种蚤指数的相关均不显著(P>0.10)。⑤ 在巢蚤中,月温度是影响巢秃病蚤唯一的气象因子(P<0.05)。⑥ 分别求出鼠体的秃病蚤和同形客蚤指名亚种Xenopsylla conformis conformis与气象因子的最优回归子集(P<0.003、P<0.05), 洞干的秃病蚤和二齿新蚤与气象因子的最优回归子集(P<0.0007、P<0.01), 月蒸发量是影响秃病蚤的最重要因子。⑦ 春季与冬季、夏季与冬季巢蚤指数差异显著(P<0.05); 春季与冬季、夏季与冬季体蚤指数差异显著(P<0.05); 春季与冬季、夏季与秋季、夏季与冬季洞干蚤指数差异显著(P<0.05)。