番木瓜抗病育种及其组培苗生产概述

概述番木瓜抗病育种研究进展及发展趋势,阐述番木瓜种苗组织快繁技术的优点及具体步骤,为抗病、优质、高产番木瓜优良品种的遗传稳定性的保持及其种质的保存提供了一条有效途径。     

大蒜扩展蛋白基因AsEXPA8的分离及其参与渗透胁迫响应的分析

扩展蛋白在植物生长发育和应对环境变化等过程中发挥重要作用。为了解大蒜扩展蛋白基因的序列特征及其在渗透胁迫下的功能,利用逆转录PCR(RT-PCR)方法从大蒜中克隆得到AsEXPA8基因,采用NCBI、ExPASy、SignalP 5.0和STRING等网站以及DNAMAN和MEGA 5.1软件对其序列进行分析,并采用实时荧光定量PCR技术对AsEXPA8基因在盐胁迫和模拟干旱胁迫下的表达特征进行研究。序列分析结果表明,AsEXPA8含有1个774 bp的开放阅读框,编码257个氨基酸。AsEXPA8蛋白有1个组氨酸-苯丙氨酸-天冬氨酸(His-Phe-Asp,HFD)基序,N端和C端分别含有8个保守的半胱氨酸残基和4个保守的色氨酸残基,具有信号肽和跨膜结构域,参与了生长素和赤霉素等激素调控细胞壁重构的过程。AsEXPA8在大蒜不同组织中均能表达,在叶片中表达相对较高。干旱胁迫和盐胁迫在不同组织内均诱导了AsEXPA8的表达。结果表明,AsEXPA8基因可能参与了大蒜植株抵御盐胁迫和干旱胁迫的过程。本研究结果为揭示AsEXPA8基因在大蒜应对渗透胁迫过程中的功能提供了理论依据。     

3种羊蹄甲属乔木的形态辨识

由于红花紫荆、羊蹄甲、宫粉紫荆这3种羊蹄甲属乔木在园林应用中非常广泛,也常常发生混淆,在此针对其叶、花、树皮、果实、种子等器官形态的不同加以辨别鉴定,为园林业界同行对其准确识别提供参考。     

土壤镉污染对大蒜生理生化指标的影响

1材料与方法1．1材料供试蒜种为山东省农科院培育的鲁蒜王（VF684）1号,选取籽粒饱满、大小均匀、健壮无损伤的蒜瓣为试材。供试土壤为青岛市郊农田0-20cm表层土壤。该土壤远离公路和居民区,属于该地特有的砂质壤土,土壤污染较轻,其pH值6．56,有机质含量25．35g/kg,速效磷、速效钾、碱解氮含量分别为91．56、24．20、42．10mg／kg,重金属全镉、全铅含量分别为0.21、45．83mg／kg。采集土壤风干后过3mm尼龙筛,备用。     

Size, symbiotic effectiveness and genetic diversity of field pea rhizobia (Rhizobium leguminosarum bv. viciae) populations in South Australian soils

Field pea (Pisum sativum L.) is widely grown in South Australia (SA), often without inoculation with commercial rhizobia. To establish if symbiotic factors are limiting the growth of field pea we examined the size, symbiotic effectiveness and diversity of populations of field pea rhizobia (Rhizobium leguminosarum bv. viciae) that have become naturalised in South Australian soils and nodulate many pea crops. Most probable number plant infection tests on 33 soils showed that R. l. bv. viciae populations ranged from undetectable (six soils) to 32×10³ rhizobia g⁻¹ of dry soil. Twenty-four of the 33 soils contained more than 100 rhizobia g⁻¹ soil. Three of the six soils in which no R. l. bv. viciae were detected had not grown a host legume (field pea, faba bean, vetch or lentil). For soils that had grown a host legume, there was no correlation between the size of R. l. bv. viciae populations and either the time since a host legume had been grown or any measured soil factor (pH, inorganic N and organic C). In glasshouse experiments, inoculation of the field pea cultivar Parafield with the commercial Rhizobium strain SU303 resulted in a highly effective symbiosis. The SU303 treatment produced as much shoot dry weight as the mineral N treatment and more than 2.9 times the shoot dry weight of the uninoculated treatment. Twenty-two of the 33 naturalised populations of rhizobia (applied to pea plants as soil suspensions) produced prompt and abundant nodulation. These symbioses were generally effective at N₂ fixation, with shoot dry weight ranging from 98% (soil 21) down to 61% (soil 30) of the SU303 treatment, the least effective population of rhizobia still producing nearly double the growth of the uninoculated treatment. Low shoot dry weights resulting from most of the remaining soil treatments were associated with delayed or erratic nodulation caused by low numbers of rhizobia. Random amplified polymorphic DNA (RAPD) polymerase chain reaction (PCR) fingerprinting of 70 rhizobial isolates recovered from five of the 33 soils (14 isolates from each soil) showed that naturalised populations were composed of multiple (5-9) strain types. There was little evidence of strain dominance, with a single strain type occupying more than 30% of trap host nodules in only two of the five populations. Cluster analysis of RAPD PCR banding patterns showed that strain types in naturalised populations were not closely related to the current commercial inoculant strain for field pea (SU303, ≥75% dissimilarity), six previous field pea inoculant strains (≥55% dissimilarity) or a former commercial inoculant strain for faba bean (WSM1274, ≥66% dissimilarity). Two of the most closely related strain types (≤15% dissimilarity) were found at widely separate locations in SA and may have potential as commercial inoculant strains. Given the size and diversity of the naturalised pea rhizobia populations in SA soils and their relative effectiveness, it is unlikely that inoculation with a commercial strain of rhizobia will improve N₂ fixation in field pea crops, unless the number of rhizobia in the soil is very low or absent (e.g. where a legume host has not been previously grown and for three soils from western Eyre Peninsula). The general effectiveness of the pea rhizobia populations also indicates that reduced N₂ fixation is unlikely to be the major cause of the declining field pea yields observed in recent times.     

沙棘产品的开发及应用前景

沙棘果肉、种子以及果渣中所富含的营养成分及活性物质具有特殊的应用价值与巨大的应用前景。对我国沙棘的地理分布、有效成分、生理功能进行了概述,重点综述了沙棘相关产品的开发,并对我国沙棘产业的近一步研究与发展进行了展望。     

豌豆多酚氧化酶的特性及抑制剂研究

对豌豆果实中多酚氧化酶(PPO)的活性及不同抑制剂的抑制效果进行研究.结果表明:该酶可迅速催化焦性没食子酸的酶促反应,而对邻苯二酚、对苯二酚和间苯二酚则催化活性较低豌豆果实中多酚氧化酶的最适pH值为8.0,最适温度为40℃,底物浓度与酶活性成正相关;抗坏血酸、柠檬酸、四硼酸钠和EDTA-2Na对豌豆果实多酚氧化酶的抑制作用依次减弱,抗坏血酸、柠檬酸对酶的抑制作用随着浓度的增大而加强.     

Phenological Development–Yield Relationships in Dry Pea in Semiarid Mediterranean Conditions

Dry pea (Pisum sativum L.) growers in the semiarid Mediterranean region require cultivars that are both early maturing and high yielding. However, negative relationships between these two characteristics limit their simultaneous improvement. A better understanding of the relative importance of the developmental stages in determining yield would assist in pea improvement. Sixteen dry pea cultivars were grown for 2 years under semiarid Mediterranean conditions (Maru, north Jordan) in order to see if differences in growing degree days (GDD) to flowering and GDD from planting to physiological maturity exist and to study their relationships with seed yield. Seed yield was negatively correlated with GDD to maturity, but not significantly correlated with GDD to flowering. Increasing GDD to flowering resulted in higher seed yield, while increasing seed fill duration had little effect. Rapid seed fill rate was positively correlated with seed weight and negatively correlated with seed fill duration. These results indicate that Mediterranean-adapted cultivars would have preflowering periods lasting as long as possible, followed by short seedfill periods. Simultaneous selection for early maturity and a relatively long time to flowering is recommended for the development of early-maturing, high-yielding cultivars adapted to semiarid Mediterranean environments.     

烯效唑(S3307)对大麦产量及延缓衰老的影响

在大麦（ＨｏｒｄｅｕｍｓａｔｉｖｕｍＬ．）拔节期喷施不同浓度烯效唑（２０、４０、６０ｍｇ／Ｌ）的试验结果表明：①喷施对产量直接影响不大,年度间反应不同,品种间存在一定差异．但各品种经烯效唑加钾混合处理后,因穗、粒、重产量构成因素均明显改善,均显著或极显著增产;②烯效唑具有延缓衰老作用,处理后明显提高大麦生育后期功能叶的光合色素含量、叶面积指数、根系活力;加钾处理能强化延缓衰老作用．其原因与生育后期保持较高的超氧物岐化酶（ＳＯＤ）和过氧化物酶（ＰＯＤ）活性有关;③提高植株总氮量,灌浆初期,促进氮元素向籽粒运转;也可进一步提高植株总钾量．加钾和赤霉素可提高烯效唑作用;④烯效唑对三类型大麦（二棱、四棱和六棱）敏感性基本一致,均有５０％左右品种（系）不敏感或敏感性较弱,１０％左右品种（系）极敏感,３５％左右品种（系）敏感性较强．     

不同比例蚯蚓粪与常规基质培育豌豆苗菜效果比较

以不同比例蚯蚓粪与常规基质珍珠岩、纸巾纸培育豌豆苗,探讨不同基质对豌豆苗菜的栽培效果。结果表明,在黄土里加入适当的蚯蚓粪作基质培育豌豆苗菜,对豌豆苗菜有明显的增产作用,其中,以含15%～30%蚯蚓粪的基质总体效果最好。