Genetic Dissection of Wheat Kernel Hardness Using Conditional QTL Mapping of Kernel Size and Protein-Related Traits

Kernel hardness (KH) is one of the primary quality parameters for common wheat (Triticum aestivum L.) and has a major impact on milling, flour quality, and end-product properties. In addition to Puroindoline (Pin) mutations and differences in Pin expression, other factors, such as kernel size and protein-related traits, play noticeable roles in determining hardness, but at the quantitative trait locus (QTL) level, the influence of these factors remains unclear. In this study, genetic relationships between KH and kernel size traits and between KH and protein-related traits were demonstrated by unconditional and conditional mapping using a wheat 90K genotyping assay with a segregating population of 173 recombinant inbred lines in four environments. Eight additive QTL for KH were detected using unconditional QTL mapping analysis; these QTL were primarily distributed on chromosomes 4B, 5A, 5B, and 6D, with phenotypic variation that ranged from 0.2 to 17.7%. In addition, one pair of epistatic QTL (QKH3B.4-65/QKH4B.6-2) was identified by unconditional mapping, and this pair accounted for 1.6% of the phenotypic variation. Through conditional mapping, after excluding the influences of kernel size and protein-related traits, 14 QTL were discovered and accounted for 0.6–18.5% of the phenotypic variation. Of them, the stable QTL QKH4B.4-17 made the largest contribution, which was partially contributed by the kernel length (KL), kernel thickness (KT), and dry gluten content (DGC). Furthermore, QKH4B.4-17 was crucially contributed by the kernel width (KW), kernel diameter (KD), kernel protein content (KPC), and wet gluten content (WGC) and was independent of the sedimentation volume (SV) and gluten index (GI). Another major QTL, QKH5B.10-63, was independent of the KW and KT; partly due to the variations in KL, KD, DGC, and WGC; and conclusively contributed by the KPC, SV, and GI. Seven additional QTL were only detected in the conditional analysis and were crucially contributed by kernel size or protein-related traits. These results demonstrated that kernel size and protein-related traits play significant roles in determining KH. The present study increases the understanding of the relationships between KH and kernel size and between KH and protein-related traits at the QTL level.     

Sinopestalotiollides A–D,cytotoxic diphenyl ether derivatives from plant endophytic fungus Pestalotiopsis palmarum

Four new diphenyl ether derivatives, sinopestalotiollides A–D (1–4), one new natural α-pyrone product (11), as well as twelve known compounds (5–1?7), were obtained from the ethyl acetate extract of the endophytic fungus Pestalotiopsis palmarum isolated from the leaves of medicinal plant Sinomenium acutum (Thunb.) Rehd et Wils. The structures were elucidated by HR-ESI-MS and NMR spectrometry data. Bioassay experiments revealed that compounds 1–4 and 11 exhibited strong to weak cytotoxicities against three human tumor cell lines Hela, HCT116 and A549.     

Effects of exogenous calcium on mesophyll cell ultrastructure,gas exchange,and photosystem II in tobacco (Nicotiana tabacum Linn.) under drought stress

Photosynthetica - The effects of calcium chloride solution (10 mmol L–1) on mesophyll cell ultrastructure, gas exchange, chlorophyll and carotenoid content, and PSII in tobacco leaf were...     

Cloning and sequence analysis of a plasmid replicon from Lactococcus lactis subsp. cremoris FG2

A replication region from one of the Lactococcus lactis subsp. cremoris FG2 plasmids was isolated by cloning of a 4.8-kb XbaI fragment into a replication probe vector and transformation into L. lactis LM0230. A 1.8-kb region within this fragment was sequenced and confirmed by PCR subcloning to encode a functional replicon in LM0230. The replicon consists of an open reading frame encoding a putative replication protein (Rep) of 386 amino acids and a non-coding region (ori) which features several structural motifs typical of other known replication origins, including a 22-bp iteron sequence tandemly repeated three and a half times, a 10-bp direct repeat and two sets of inverted repeats. The ori region could drive replication of its plasmid when supplied with the replication region in-trans. The lack of detectable single-stranded DNA during replication and the existence of extensive homology with other known lactococcal theta replicons strongly suggest that this region encodes a theta-replicating mechanism.     

Kinetic study of enantioselective esterification of ketoprofen with n-propanol catalysed by an lipase in an organic medium

A kinetic study of an immobilised lipase esterification reaction in dipropyl ether for resolution of ketoprofen indicated a Bi Bi Ping Pong mechanism with dead-end inhibition of the alcohol was occurring for both enantiomers and this is was confirmed experimentally. Parameters in the kinetic equation and reaction activation energies for the two enantiomers were determined by non-linear regression.     

Effect of α-fluoromethylhistidine-evoked histamine depletion on ultrastructure of endocrine cells in acid-producing mucosa of stomach in mouse,rat and hamster

The oxyntic mucosa of the mammalian stomach is rich in endocrine cells, such as ECL cells, A-like cells, somatostatin cells, D₁/P cells and, in some species, enterochromaffin cells. The various endocrine cell types can be distinguished on the basis of their characteristic cytoplasmic granules and vesicles. The ECL cells contain numerous large secretory vesicles and relatively few, small electron-dense granules and small clear microvesicles. We have suggested that in the rat the ECL cells contain most of the gastric histamine with the secretory vesicles as the major histamine storage site in these cells. α-Fluoromethylhistidine is an irreversible inhibitor of histidine decarboxylase, the histamine-forming enzyme. We have previously shown that this enzyme inhibitor depletes histamine from the ECL cells in the rat and reduces the number of secretory vesicles in the cytoplasm. In the present study, we have examined whether α-fluoromethylhistidine affects the ECL cells in other species and whether it affects other types of endocrine cells in the oxyntic mucosa of the rat. Mice, rats and hamsters were treated with the inhibitor (3 mg/kg per h) via minipumps subcutaneously for 24 h. This treatment lowered the oxyntic mucosal histamine concentration by 65–90% and the number and volume density of the secretory vesicles by 85–95% in the ECL cells of the three species examined. In contrast, the number and volume density of granules and microvesicles were not greatly affected. No evidence was found for an effect of α-fluoromethylhistidine on A-like cells, somatostatin cells or D₁/P cells of the rat stomach, suggesting that, unlike the ECL cells, they do not contain histamine. Received: 18 January 1996 / Accepted: 23 May 1996     

In vitro propagation of Phalaenopsis via culture of cytokinin-induced nodes

A new procedure for in vitro propagation of orchids belonging to the genus Phalaenopsis was developed. In contrast to commonly employed propagation methods that make use of leaf, root, or shoot tip tissues, we have used elongated stems of 6-benzyladenine-induced young seedlings as starting material for propagation. The elongated stem consisted of several nodes of which top nodes were used for cyclic propagation of new explants and the middle nodes for producing shoots or multiple adventitious buds. The whole procedure of proliferation could be completed within 7 months, and about 2,300 plantlets were produced from a single induced stem in a single year. This method may be used for propagation of seedlings in the case of lack of seeds in orchid breeding or for propagation of vegetative buds developed on flower stalks of rare orchid varieties when available flower stalks are limited. It may also have great potential for the propagation of wild threatened orchid species.Abbreviations PLB(s) protocorm-like body(ies) - zeatin 6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine - 2ip 6-(,-dimethylallylamino)purine - kinetin 6-furfurylaminopurine - BA 6-benzyladenine     

茶果（林）复合园的光特征研究

茶果（林）复合园上层林冠透光率落叶树种比常绿树种高２～１５％,春季可高出３０％左右,透光率维持大于５５％水平对茶叶产量影响不显著．林冠下的散射量１２～１４时已超过２．９Ｊ·ｃｍ－２·ｍｉｎ－１的茶树光饱和点水平落叶树下散射光量占总辐射量春季达６５～８０％,夏、秋季４５～６０％茶树树冠面反射光量占总辐射量比例小,晴天约为５～８％,年变辐为５～１０％,日变幅以１０～１５时最高,夏、秋季高达０．２～０．４Ｊ·ｃｍ－２·ｍｉｎ－１茶树树冠透射光量在５００～２０００ｌＸ,日变化以１６～１７时透射率最高约１５～２０％,茶树吸收光占总量８０～８５％