秦巴山区野生百合(Lilium spp.)的育种应用研究

为探索秦巴山区野生百合资源在百合育种中的应用方向及途径, 获得具有其独特遗传背景的育种材料,将秦巴山区野生百合的抗病毒及独特观赏特性等优良遗传性状逐渐渗到栽培品种中去。该研究借助切割柱头杂交及胚抢救技术,选取6种秦巴山区野生百合［岷江百合(Lilium gegale)、宜昌百合(L. leucanthum)、山丹（L. pumilum）、野百合（L. brownii）、宝兴百合（L. duchartrei）、川百合（L. davidii）］以及亚洲百合（Asiatic hybrids,AA）品种‘Elite’、东方百合（Oriental hybrids,OO）品种‘Sorbonne’、‘Siberia’和‘Marlon’、OT百合（Oriental × Trumpet hybrids,OT）品种‘Yelloween’、‘Serano’、‘Corel′door’进行了32组共计263朵花的（品）种间杂交,并针对膨大变软的果实剥离可供离体培养的胚及胚囊进行胚抢救。结果表明：（1）不同杂交组合坐果率、胚获得及萌发率呈现出较大差异,综合坐果率为11.4%,对30个膨大的果实中共计38个可供离体培养的胚及胚囊进行胚抢救,有7株最终萌发。（2）以野生百合为父母本的12组杂交组合中,6组获得了膨大果实,得到6株杂交后代。（3）栽培百合做母本,野生百合做父本的20组杂交组合中,共9组获得了膨大果实,除‘Elite’ × 山丹可直接收获种子外,共得到1株杂交后代。（4）以岷江百合及宜昌百合为亲本的远缘杂交TT × AA及回交OT × TT成功获得杂种后代。（5）秦巴山区6种野生百合在远缘杂交中获得育种后代的几率存在较大差异,宜昌百合和岷江百合获得后代几率较高,宝兴百合获得后代几率较低,野百合未获得后代。以上结果表明,岷江百合和宜昌百合为母本的TT × AA杂交和宝兴百合为父本的TT × AA杂交以及岷江百合和宜昌百合为父本的OT回交,为三种百合的育种利用提供了新途径,野百合的育种应用途径需要继续探索。     

中亚热带不同母质和森林类型土壤生态酶化学计量特征

土壤生态酶化学计量比作为衡量土壤微生物能量和养分资源限制状况的重要指标,是当前生态学领域研究的热点之一,然而关于土壤母质和森林类型在调控土壤生态酶化学计量比中所扮演的角色及作用机制尚不明确。分别以砂岩和花岗岩发育的米槠林和杉木林土壤为研究对象,通过测定土壤物理化学性质、微生物量碳、氮和磷及土壤酶活性,探讨不同母岩发育的米槠林和杉木林土壤生态酶化学计量特征。结果显示,花岗岩发育的土壤酸性磷酸酶活性(AP)显著高于砂岩发育的土壤,βG:AP和NAG:AP的值显著低于砂岩发育的土壤。其中,花岗岩发育的米槠林土壤βG:AP和NAG:AP的值都显著高于杉木林,砂岩发育的土壤βG:AP和NAG:AP的值在两个林分间呈相反的结果。结果表明土壤生态酶化学计量比能够反映不同森林土壤之间磷养分限制强度,花岗岩比砂岩土壤受磷养分限制更严重。相关分析表明,土壤酶活性及生态酶化学计量比与土壤生物因子和非生物因子密切相关,而冗余分析发现土壤pH、总磷(TP)和微生物量碳(MBC)分别解释土壤酶活性和生态酶化学计量比变异的56.9%、27.9%和12.3%。未来森林经营及管理应考虑土壤母质和森林类型差异对区域森林土壤养分循环的影响。     

Construction of a cross-species cell landscape at single-cell level

Individual cells are basic units of life. Despite extensive efforts to characterize the cellular heterogeneity of different organisms, cross-species comparisons of landscape dynamics have not been achieved. Here, we applied single-cell RNA sequencing (scRNA-seq) to map organism-level cell landscapes at multiple life stages for mice, zebrafish and Drosophila. By integrating the comprehensive dataset of > 2.6 million single cells, we constructed a cross-species cell landscape and identified signatures and common pathways that changed throughout the life span. We identified structural inflammation and mitochondrial dysfunction as the most common hallmarks of organism aging, and found that pharmacological activation of mitochondrial metabolism alleviated aging phenotypes in mice. The cross-species cell landscape with other published datasets were stored in an integrated online portal—Cell Landscape. Our work provides a valuable resource for studying lineage development, maturation and aging.     

Variations of cuticular wax in mulberry trees and their effects on gas exchange and post-harvest water loss

Though mulberry (Morus alba) tree shows great adaptations to various climate conditions, their leaf water status and photosynthesis are sensitive to climate changes. In the current study, seven widely planted mulberry cultivars in Chongqing, Southwest China, were selected to analyze leaf cuticular wax characteristics, gas exchange index, post-harvest leaf water status and their relationships, aiming to provide new theory in screening high resistant mulberry cultivars. Mulberry trees formed rounded cap-type idioblasts on the adaxial leaf surface. Film-like waxes and granule-type wax crystals covered leaf surfaces, varying in crystal density among cultivars. The stomatal aperture on the abaxial surface of cultivars with high wax amount was smaller than that of cultivars with low wax amount. The amount of total wax was negatively correlated with the net photosynthetic rate (P _N), transpiration rate (E) and stomatal conductance (g _s) and positively correlated with the moisture retention capacity. It suggested that both cuticular wax and stomatal factor might be involved in regulating water loss in mulberry leaves under field conditions. The variability in moisture retention capacity and cuticular wax characteristics might be important in evaluating and screening mulberry cultivars for increasing silk quality and silkworm productivity.     

Detection of Cytomegalovirus Antibodies Using a Biosensor Based on Imaging Ellipsometry

Background

Cytomegalovirus (CMV) is the most common infectious cause of mental disability in newborns in developed countries. There is an urgent need to establish an early detection and high-throughput screening method for CMV infection using portable detection devices.

Methods

An antibody analysis method is reported for the detection and identification of CMV antibodies in serum using a biosensor based on high spatial resolution imaging ellipsometry (BIE). CMV antigen (CMV-3A) was immobilized on silicon wafers and used to capture CMV antibodies in serum. An antibody against human immunoglobulin G (anti-IgG) was used to confirm the IgG antibody against CMV captured by the CMV-3A.

Results

Our results show that this assay is rapid and specific for the identification of IgG antibody against CMV. Further, patient serum was quantitatively assessed using the standard curve method, and the quantitative results were in agreement with the enzyme-linked immunosorbent assay. The CMV antibody detection sensitivity of BIE reached 0.01 IU/mL.

Conclusions

This novel biosensor may be a valuable diagnostic tool for analysis of IgG antibody against CMV during CMV infection screening.     

Diphenyl difluoroketone: a potent chemotherapy candidate for human hepatocellular carcinoma

Diphenyl difluoroketone (EF24), a molecule having structural similarity to curcumin, was recently reported to inhibit proliferation of various cancer cells significantly. Here we try to determine the effect and mechanism of EF24 on hepatocellular carcinoma. 2 μM EF24 was found to inhibit the proliferation of PLC/PRF/5, Hep3B, HepG2, SK-HEP-1 and Huh 7 cell lines. However, even 8 μM EF24 treatment did not affect the proliferation of normal liver LO2 cells. Accordingly, 20 mg/kg/d EF24 inhibited the growth of the tumor xenografts conspicuously while causing no apparent change in liver, spleen or body weight. In addition, significant apoptosis and G(2)/M phase cell cycle arrest were found using flow cytometry. Besides, caspases and PARP activation and features typical of apoptosis including fragmented nuclei with condensed chromatin were also observed. Furthermore, the mechanism was targeted at the reduction of nuclear factor kappa b (NF-κB) pathway and the NF-κB-regulated gene products Bcl-2, COX-2, Cyclin B1. Our study has offered a strategy that EF24 being a therapeutic agent for hepatocellular carcinoma.     

He-Ne激光对小麦属间杂交影响的研究

1988年以来,作者采用He-Ne激光辐照黑麦花粉与杂交相结合的新方法,对小麦属间杂交(普通小麦×黑麦)进行了研究,获得了较好的效应.试验采用随机区组排列,重复三次,单粒条播.辐照方法,采用He-Ne激光分别以100秒、200秒、300秒辐照三个黑麦品种的花粉,与普通小麦授粉,配制成9个(普通小麦×黑麦)属间杂交组合.所得结果,采用方差分析、新复极差测验法,测定了组合与对照组合相比的差异显著性,也测定了各组合间相互比较的差异显著性.激光辐照小麦属间杂交所获种子的结实率极显著高于对照,为113.52～341.60%.籽粒千粒重和饱满度均超过对照,分别为84.07～295.43%、30.30～127.27%,差异均极显著.L1代籽粒出苗率和植株成活率分别比对照提高58.18～83.06%、41.35～87.78%,差异达到极显著水平.He-Ne激光的诱变作用,在于促进了小麦属间杂交的可交配性,提高了杂交籽粒的结实率,改善了籽粒的饱满度,提高了籽粒的千粒重,因而促进了杂种种子的出苗率和成活率.并且,在L1代植株中均获得了染色体自然加倍的双二倍体即小黑麦种子.现已获得L1～L8代的小黑麦后代材料和稳定株系.高科技的激光诱变育种,为小麦属间杂交育种工作开辟了新的简便途径.