荚用菜豆松散型胚性愈伤组织保持体系的诱导方法

本研究旨在为诱导再生成苗提供基础材料,为进一步开展荚用菜豆育种相关研究奠定基础。以荚用菜豆无性细胞（茎、叶、子叶等器官）为试验材料,通过筛选植物激素及其最佳组合,获得了以细胞质浓密的圆球形细胞为主体的松散型愈伤组织细胞团。最终筛选出诱导无性细胞产生普通愈伤组织的“诱导培养基Ⅰ号”：MS +2,4-D 1 mg/L+蔗糖30 g/L。进一步研究获得了“诱导培养基Ⅱ号”：MS + 6-BA 0.25 mg/L + 2,4-D 0.5 mg/L+ AgNO₃ 10 mg/L。此培养基可以诱导和保持松散型胚性愈伤组织。本研究筛选出可以将无性细胞诱导为松散型胚性细胞团,并且维持胚性细胞继续增殖的系列培养基,解决了诱导过程中愈伤组织褐化问题,创建了一套诱导荚用菜豆松散型胚性愈伤组织的新方法。     

灌溉条件下长期定位施肥对塿土剖面养分分布特征的影响

对塿土12年连续施肥后土壤剖面养分分布的研究发现,施肥使有机质、全P在耕层（0～20cm）与CK比较有不同程度的增加;施肥可以显著影响0～200cm土壤剖面有机质的含量;PK处理土壤剖面存在P素适度下移,120～220cm全磷含量呈现峰值;施肥对塿土耕层及0～300cm剖面全K含量几乎无影响;塿土粘化层可以减缓养分的下移;氮磷钾化肥与有机肥配合施用,使土壤NO3--N与CK比较有适度增加,对培育土壤肥力有利。     

Unveiling various spatial patterns of determinants of hukou transfer intentions in China: A multi-scale geographically weighted regression approach

As the floating population has become a vital issue influencing China's economic and social development and aroused broad concern, many scholars have paid attention to the factors that influence settlement intentions of the floating population, while their spatial differences are usually neglected in extant studies. To rectify this situation, this study employs a multi-scale geographically weighted regression model to investigate the spatial pattern of determinants on hukou transfer intentions of the floating population, based on the data of the China Migrants Dynamic Survey in 2016. The results demonstrate that the effects of various determinants present different spatial patterns: part of significance pattern (the average residence time in destination cities, the ratio of rural hukou holders, the number of flows, the ratio of family income to family expenditure, the geographical location), the “East-West” pattern (the ratio of self-employed migrants, the average wage of employed workers), the “Southwest-Northeast” pattern (the ratio of migrants in the secondary industry, the ratio of sharing town employees' social insurance, the ratio of floating population accompanied by children in destination cities, and the population density of municipal districts). Cities of different conditions should formulate different policies that are sensitive to their contexts.     

低糖保健咖啡风味巧克力的开发与研究

以可可液块、咖啡、黑豆、黑芝麻等为主要原料,研究了咖啡风味巧克力的主要配方,确定咖啡风味巧克力的最佳配方为:可可液块∶蔗糖∶咖啡∶黑豆∶黑芝麻∶可可脂∶乳粉=50∶25∶4∶2∶4∶20∶20,香兰素和大豆磷脂的添加量保持恒定比例为0.01%和0.4%,制备出色、香、味俱佳,并且有丰富保健功能的的风味巧克力,此种巧克力在常温下保存质量稳定。     

砂田降雨入渗过程的模拟实验研究

砂田是一种具有综合效能的旱作技术,在干旱半干旱地区得到了不同程度的应用。为了研究砂石覆盖下降雨入渗的规律,笔者进行了室内模拟实验,对土壤水分的动态变化过程进行了研究。结果表明：在模拟降雨过程中,砂石覆盖下土壤的累计产流量一直低于裸土,说明砂石覆盖有利于减少土表降雨产流。砂石覆盖的土壤的各个深度土壤含水率均比裸土对照组要高,表明砂石覆盖有降雨入渗到土壤中。在经过一定时间的降雨后,砂石覆盖土柱中不同深度的土壤含水率变化会趋于稳定,且数值接近,表明砂石覆盖的土壤比裸土更快地进入稳渗阶段。     

High frequency spontaneous production of doubled haploid plants in microspore cultures of Brassica rapa ssp. chinensis

Brassica rapa (syn. Brassica campestris) ssp. chinensis is an important vegetable crop, but it is relatively recalcitrant to microspore culture. One genotype each of B. rapa ssp. chinensis var. communisand var. utilis were used formicrospore culture. Embryo production of3.8–42.4 embryos/bud was obtained. A high rate of plant regeneration directly from microspore-derived embryos without subculture was achieved by an improved protocol involving replacement of culture media and reduction of sucrose concentrations after 48 h of induction,among other modifications. More than 70%of regenerated plants were spontaneous diploids. Some spontaneous tetraploid plants were also obtained from isolated microspores of both genotypes tested. These tetraploids may be directly exploited a snew varieties in a Brassica rapabreeding programme. This revised version was published online in July 2006 with corrections to the Cover Date.     

菜用大豆耐低温弱光鉴定方法和评价指标的研究

为建立一套有效、可靠的菜用大豆耐低温弱光鉴定方法和评价指标,选择12个熟性不同的春播型菜用大豆品种材料,通过对其在低温弱光胁迫下种子发芽快慢、幼苗存活率及相关生理生化指标等的检测分析,鉴定各品种材料对低温弱光逆境胁迫反应的差异。结果表明,在弱光低温组合60~80 μmol/(m2?s)、12℃的逆境胁迫下,12个菜用大豆品种材料的出苗快慢、幼苗存活率及叶片中SOD、POD及CAT活性等存在差异,相关分析表明保护性酶活性与光温组合呈极显著正相关。     

离心对蒺藜苜蓿花药愈伤组织生长和分化的影响

以蒺藜苜蓿杂交F1代花药为材料,检测了离心力、离心时间对不同基因型花药愈伤组织诱导、生长及分化的影响。结果表明：离心能促进花药愈伤组织的形成;对A基因型花药的诱导作用更明显;不同离心力处理的花药愈伤组织诱导率差异极显著（P<0.01）,其中1000×g,2 min的效果最好;离心对愈伤组织的生长无明显影响,但对抗氧化酶的活性强弱有影响;随离心力的增大,过氧化物酶（POD）的活性逐渐增强,其变化趋势与过氧化氢酶（CAT）和超氧化物歧化酶（SOD）的相反。     

陆地棉GhDAHP基因的克隆与表达分析

棉花黄萎病是制约棉花产业健康发展的一种重要病害,在生产上未发现有效的根治办法,使用现代基因工程技术,从基因库中挖掘抗黄萎病相关基因,为棉花抗黄萎病育种工作的提供理论基础。本研究根据在GenBank中检索到抗黄萎病基因SDAHP(GU479467,1,3-脱氧-阿拉伯庚酮糖-7-磷酸合成酶),从陆地棉基因组数据库中检索到3个同源基因(NM_016893351.1,XM_016849738.1和XM_0168151150.1),根据3个同源基因核苷酸序列设计引物,以陆地棉cDNA为模板进行克隆,获得3个目的基因,依次命名为GhDAHP-1、GhDAHP-2和GhDAHP-3。利用ProtParam和Prot Scale等在线软件对目的基因进行生物信息学分析;RT-PCR分析黄萎病菌诱导后目的基因在陆地棉叶片中的表达量。结果表明:GhDAHP-1序列全长1983 bp,氨基酸总数为539,分子质量约59.45378 kD,理论等电点pI为8.7;GhDAHP-2序列全长1832 bp,氨基酸总数516,分子质量约57.02998 kD,理论等电点pI为7.68;GhDAHP-3序列全长1652 bp,氨基酸总数517,分子质量约56.95491 kD,理论等电点pI为8.52。系统进化树分析,GhDAHP与雷蒙德氏棉(Gossypium raimindii)、木本棉(Gossypium arboreum)的亲缘关系最近。棉花叶片在黄萎病菌的处理下,GhDAHP基因表达量呈现先升高后降低的趋势,推测受到黄萎病诱导后,GhDAHP基因可能参与了黄萎病菌侵染的防卫过程。     

饲料膨化技术研究进展及应用分析

膨化技术在国内饲料加工业已得到广泛认可和应用,但国内对膨化及相关技术的研究仍很薄弱,对近些年国际上膨化技术进展及应用进行了阐述,如加压切割(模后加压)控制膨化产品密度,使用废蒸汽余热进行调质,以及膨化技术在猪和反刍动物饲料中的应用等。