北五味子优良家系选择及设施栽培技术

五味子家系间果粒数、果径、单果重3个性状差异极显著,通过对果实性状进行变异分析与综合评价,确定02号、10号、03号家系为优良家系,且3个家系单果重量较对照(CK)分别提高33.24%、26.73%、15.86%,果实直径较对照(CK)分别提高9.28%、12.06%、16.16%。设施栽培采取50cm×50cm×35cm穴状定植方式,株行距0.35m×1.00m;以多枝蔓形式整形效果最佳,全株保留2～4条主蔓,主蔓间距15～20cm,并在主蔓枝上每20～30cm培养一个固定结果枝。     

从《颜氏家训》看南朝士族衰落的原因

士族阶层在南朝逐渐衰落是学术界的共识,但对其衰落的原因却有不同看法。颜之推亲历了梁、北齐、北周、隋四个朝代,在《颜氏家训》中他虽对南朝士族的衰落没有直接描述,但仍是我们分析南朝士族衰落原因不可多得的宝贵资料。     

高校家庭经济困难学生认定及名额分配的实践探索——以河北农业大学为例

本文从高校对家庭经济困难学生的认定和名额分配的总体情况入手,指出其认定和名额分配过程中存在的不足,并以河北农业大学为例,探讨了该校对家庭经济困难学生的认定和名额分配的全面广泛的认定方法、综合平衡的分配方法、方法改良后的实施效果,进而有针对性地提出完善认定标准,核准救助范围;培养学生的诚信意识,提高认定效率;建立科学高效的监督体系,加强助困资源分配的公平性等对策建议。     

Quantitative trait loci for leg weakness traits in a Landrace purebred population

Leg weakness in pigs is a serious problem in the pig industry. We performed a whole genome quantitative trait locus (QTL) analysis to find QTLs affecting leg weakness traits in the Landrace population. Half-sib progeny ( n  = 522) with five sires were measured for leg weakness traits. Whole genome QTL mapping was performed using a half-sib regression-based method using 190 microsatellite markers. No experiment-wide significant QTLs affecting leg weakness traits were detected. However, at the 5% chromosome-wide level, QTLs affecting leg weakness traits were detected on chromosomes 1, 3, 10 and 11 with QTL effects ranging from 0.07 to 0.11 of the phenotypic variance. At the 1% chromosome-wide level, QTLs affecting rear feet score and total leg score were detected on chromosomes 2 and 3 with QTL effects of 0.11 and 0.13 of the phenotypic variance, respectively. On chromosome 3 and 10, some QTLs found in this study were located at nearby positions. The present study is one of the first reports of QTLs affecting fitness related traits such as leg weakness traits, that segregate within the Landrace population. The study also provides useful information for studying QTLs in purebred populations.     

绒毛白蜡‘青碧’不同半同胞家系的耐盐性评价

【目的】为充分利用杂种优势,从白蜡杂交种中筛选出优良耐盐株系,【方法】采用盆栽试验方法,研究了不同浓度NaCl(0‰、2‰、4‰、6‰)胁迫对绒毛白蜡新品种‘青碧’不同半同胞家系子代苗的生长量、膜透性、丙二醛(MDA)含量、脯氨酸(Pro)含量、超氧化物歧化酶(SOD)以及叶绿素含量的影响,并结合隶属函数法综合评价4个白蜡杂交组合一年生苗的抗盐能力强弱。【结果】1)盐胁迫抑制了各半同胞家系子代的生长量,随着NaCl浓度的提高,各组杂交苗的苗高增长量、地径增长量均呈下降趋势,其中68号、70号杂交苗的下降幅度相对较小;盐胁迫对不同亲本的杂交子代生理指标的影响不一致:2)膜透性、MDA含量、脯氨酸含量均呈现出逐渐升高的趋势,68号杂交苗的膜透性及MDA含量受影响最小,70号杂交苗的脯氨酸含量增长幅度最大;各组杂交苗的SOD活性变化规律不一致,70号杂交苗的SOD活性增长幅度最大,其次为68号;3)叶绿素含量变化也无一致规律,在6‰浓度下,68号杂交苗的叶绿素含量最高。【结论】利用隶属函数法对4组杂交子代苗的耐盐性进行综合评价,各杂交材料耐盐性强弱顺序为:68号> 70号> 69号>‘青碧’半同胞。研究结果可为选育白蜡优良耐盐新品种提供理论依据和种质材料。     

杉木种子园单亲子代测定研究

对福建省８个初选家系进行子代测定，采用随机区组设计，１８次重复，对１年生、２年生、３年生和１０年生的高、径、冠幅、轮盘数、分枝数和材积等性状进行测定，试验结果表明：沙县４８号家系为中选家系，各项生长显著高于其它家系，１０年生材积生长比总体平均高２２．７％，比对照高２６．０％，可作为营建杉木一代改良种子园的材料。     

Genetic variation in seasonal growth patterns in radiata pine in Galicia (northern Spain)

Shoot elongation patterns in 2 and 3-year-old Pinus radiata seedlings were monitored twice a month during 2003 and once a month during 2004 in three progeny tests in northern Spain. Fifty-eight half-sib families were studied. Several annual growth parameters were measured in each seedling: initiation, termination and duration of height growth and number of new buds formed each year. Total height, internode length and frost resistance were also measured in each seedling. The variation in these traits among families and sites was studied, as well as the effects of environmental parameters (temperature and rainfall) on growth phenology patterns. The extent to which bud phenology is genetically controlled and related to growth traits was examined. Families differed significantly in total summer shoot growth and number of summer flushes (lammas growth). The number of cycles produced per year ranged from one to four. Monocyclic families grew throughout the year, whereas polycyclic families grew episodically, depending on rainfall.     

马占相思22个家系生长规律及优良家系筛选

以福建省岩溪林场2002年营造的马占相思家系试验林为对象,在2005年、2006年和2007年调查了马占相思22个家系的树高、胸径和冠幅,以筛选优良家系。结果表明：家系1号、2号、6号、9号、12号生长较快,其树高较高,胸径较大,是速生能力较强的优良家系,为营林提供可行性依据。     

基于TTC自交一代家系的粳稻品质性状遗传分析

运用3倍体的遗传模型对粳稻丙8979和C堡为亲本产生的TTC自交一代家系稻米品质进行了遗传分析.结果表明,垩白米率性状存在显著的上位性效应,糙米率、精米率、精米粒长、精米粒宽、长宽比、糊化温度、胶稠度、直链淀粉含量8个品质性状存在极显著的上位性效应,垩白大小性状未检测到显著的上位性,其遗传变异主要由加性、显性效应所引起,且加性变异分量起着主要作用.     

西南桦优良家系的早期选择研究*

 以广西壮族自治区、云南省的25个地区的407个西南桦家系为材料，主要从西南桦优良种源选择、苗期优良家系选择、及2年生西南桦优良家系选择3方面着手，系统分析了其蓄积量、遗传增益的变化。结果表明：407个家系中，经过苗期选择有381个优良家系上山造林；2年生西南桦381个家系中，有184个家系为Ⅰ类优良家系，其各性状的遗传力皆大于0.9，其子代可获得更高遗传增益；表现最好的家系是K6，其实际增益达112.58%，其次是K4，实际增益达94.43%。