莫桑比克60个腰果品系果梨抗白粉病调查初报

在莫桑比克楠普拉省调查了白粉病对60个腰果品系果梨的为害情况。结果显示,在相同的栽培条件下,不同腰果品系的果梨受白粉病为害程度差异很大。品系AZA17/79受白粉病的为害程度最低,为害率和为害指数分别仅为3.7%和0.91%,其次为H1、M96-2.3VM、AC34、4.2VM和Local 3,为害率在9.4%～20.4%,为害指数在4.87%～10.28%。其余品系的果梨为害率和为害指数相对较高。根据本文的腰果品系对白粉病抗性的评价标准(果梨),对60个腰果品系的果梨抗白粉病进行了评价,结果表明:高抗品系有5个,分别为AZA17/79、H1、M96-2.3VM、AC34和4.2VM;抗性品系5个,分别为Local 3、B4、2.4PA、1.20VM和11.9PA;中抗品系3个,分别为CCM9-61、AC10/14和5.12PA;感病品系6个,为AC6、9.1NAS、7.1PA、1.12PA、12.8PA和12.9PA;其余41个品系均属于高感品系。说明莫桑比克推广种植的腰果品系的果梨对白粉病抗性普遍较差,容易遭受白粉病为害。     

莫桑比克不同腰果品系对叶果回枯病的抗病性调查研究

在田间自然发生条件下,研究莫桑比克9个高产优良腰果品系对叶果回枯病的抗病性。结果表明:腰果品系4.1AD叶片高感,果实感病;腰果品系5.12PA叶片和果实均为感病;腰果品系CCS27和CM8均为叶片感病,果实中抗;腰果品系A103叶片中抗,果实高抗;腰果品系H1叶片高抗,果实中抗;腰果品系7.10PA、19.5AD和C5.59叶片和果实均为高抗。在参试腰果品系中,未发现叶片免疫品系,也未发现果实高感或免疫品系。     

东方市腰果寒害影响因素分析

2008年1～2月海南省遭遇罕见的低温阴雨天气,对腰果造成严重寒害。本文调查东方市腰果寒害情况,分析其影响因素。结果表明,东方市腰果受寒害严重,新龙镇三个果园的腰果花穗全部受寒害干枯,板桥镇果园的腰果花朵被冻死干枯,部分腰果植株被冻死干枯遥腰果植株受寒害程度与腰果品系、果园管理水平、温度以及施肥等因素有关。种植腰果无性系、加强果园管理以及合理施肥都有助于提高腰果植株的耐寒力。在正交设计的9个施肥处理中,以N3P3K2处理[N800g/(a窑株),P2O5300g/(a窑株),K2O300g/(a窑株)]的干枯植株比例最低。     

橡胶高截干苗定植后回枯的原因及防止措施

高截干苗是优良的种植材料。它对缩短大田非生产期和提高开割率有显著的效果。马来西亚研究院试验结果认为:采用高截干苗定植和改良的农业措施,可在植后3（1/2）年达到开割标准。我国广东大丰农场,58年布置了高截干苗定植技术试验,其中有两个处理七周年开割率达80.4——84.4％,比对照芽接桩定植的开割率高20.9—24.9％。本省诏安红星农场纳塘65年定植高截干苗183株,六周年开割率达70.4％。本所寨林山73年定植高截干苗400多株,预计八周年开割率可达50％。但是高截干苗对定植技术要求较严格,现将初步调查情况介绍如下: 一、定植后回枯的原因 回枯主要是苗木过分缩水的结果。图为77年高截干苗定植第一年茎围生长曲线。从     

5个不同腰果品系对茶角盲蝽的抗虫性

田间自然发生条件下,研究5个不同腰果品系对茶角盲蝽的抗虫性。结果表明:CP63-36和FL30的抗虫性最弱,均为高感品系,大面积推广种植时应注意茶角盲蝽的防治;HL2-13也有较强的抗虫性(中抗);GA63的抗虫性较弱(感虫);HL2-21对茶角盲蝽的抗虫性最强,为高抗品系,可作为抗茶角盲蝽的优良育种材料。     

香蕉母株采果后截干高度对子株的产量及生育期的影响

香蕉母株采果后,对其残干作三种高度的截除处理后观测子株的生长及产量。结果表明,高截干(2米)的与低截干(10厘米)的相比,果穗重量提高了4.6公斤(12％),收获期缩短18天(15％);中间截干(1米)的,果穗重量居中,但收获期与高截干的并无差别。果稳重量的增加是因每个果穗中果指数增多,而果指大小不变。 用试验开始时的子株假茎高度作为协变量来作结果分析。子株高度增加范围在115～217厘米内的,果穗重量亦随之相应地增加了16.5公斤,且生产周期缩短了113天。     

橡胶六点始叶螨Eotetranychus sexmaculatus(Riley)的生物学研究

发现六点始叶螨在海南岛一年可有23代,卵到成螨的发育期,成螨期和生活历期分别为8.7±0.7～28.4±2.4天,10.3±6.5～32.0±17.5天和19.2±5.1～55.6±13.7天。雌雄螨一生均能交配多次,每代平均产卵量为11.1±8.1～39.4±24.7个,雌螨一生的产卵量为1～114个,每个雌螨每天的产卵量为1～5个,卵的孵化率在95％以上,雌雄性比为1.8:1(雌螨/雄螨)。同一橡胶品系不同物候期的叶片对六点始叶螨的发育期,成螨期与产卵量有明显的影响,但品系的不同则无明显影响。     

柱花草品系的灰色关联度分析

采用灰色关联度分析法对18个柱花草品系的8个农艺性状进行综合评价。结果表明,品系TPRC 2001-47、TPRC 2001-46和TPRC 2001-71的综合表现最好,其中有6个品系优于对照热研2号。等权关联度与加权关联度分析结果基本一致,分析结果与柱花草的实际表现一致。不同性状与鲜草产量的关联度不同,7个性状与鲜草产量的关联度排序为：干物率＞第1分枝日平均生长速度＞株高日平均生长速度＞刈割时株高＞越冬存活率＞刈割时第1分枝长＞草丛宽。     

不同施氮量对双季早稻机插秧苗素质及产量的影响

以早稻品种中嘉早17和中早39为材料,设置5个不同氮肥水平(纯氮0、0.8、1.6、2.4、3.2 g/盘),探讨不同氮肥水平下水稻机插秧苗素质差异及对产量的影响。结果表明,随施氮量增加,秧苗含氮量增加,但成苗率降低,氮素积累量为先增加后下降趋势,在2.4 g/盘处理达最大;不同施氮量对两品种秧苗素质的影响存在差异,适宜的施氮量有利于提高秧苗素质,以27 d秧龄的影响较大。两品种不同施氮量下水稻产量均以1.6 g/盘的处理较高,与不施氮处理相比,增幅分别达24.14%、7.73%,产量增加主要与有效穗数的增加有关。综合这2个品种秧苗素质及机插后的产量效应,确定每盘施氮量宜为1.6~2.4 g。     

大豆籽粒品质对干豆腐加工特性的影响及适用性评价

选用来自黑龙江和吉林两省区的25个大豆品种(品系),进行干豆腐加工,对大豆品种原料理化指标、干豆腐品质特性指标等进行测定、分析,并对不同大豆品种的干豆腐加工适用性进行评价。结果表明:不同大豆品种理化指标及干豆腐品质指标均呈现了较大的差异。大豆品种籽粒品质指标与干豆腐品质指标之间存在复杂的相关关系,籽粒蛋白含量、水溶性蛋白含量与干豆腐品质指标存在显著或极显著正相关关系,籽粒脂肪含量、7S的含量与干豆腐品质指标呈显著或极显著负相关关系。通过基于因子分析的大豆品种加工干豆腐适用性评价,筛选出东农42、吉育204、东农48、2010-60和2003-342-24-4共5个干豆腐加工品质优良的大豆品种(品系)。     

A search for anthracnose resistant cashew cultivars in Mozambique

Dwarf and common cashew (Anacardium occidentale) genotypes were screened separately for resistance against anthracnose (Colletotrichum gloeosporioides). Disease incidence was assessed on emerging leaves over three consecutive crop seasons in Mocuba, Meconta and Pebane districts of northern Mozambique. Evaluation the disease using leaf incidence is presented as a new field method for screening cashew genotypes resistant to anthracnose. It is fast, precise and consistent in ranking cultivars over several tree seasons. Seasonal, cultivar and disease incidence means were compared using Fishers' LSD test. The method enabled the differentiation of highly infected cultivars from those consistently tolerant across seasons and locations. No a single clone with a high level of resistance was identified out of 229 entries. However, hierarchical tables of clonal sensitivity ranked clones 1.12PA, 12.8PA and 1.18PA as tolerant and 11.9PA and 2.3BG as susceptible among the dwarfs. Among the common genotypes, clones NA7, MB77, 1.5R and MCH-2 ranked tolerant and IM1 and MU3 susceptible. Tolerant clones were therefore recommended to be used in the national cashew breeding program for further development of cashew cultivars with durable resistance to anthracnose. Further, clones such as 2.5VM, 1EM, MB75 and others that revealed incidence consistency over seasons can be used as susceptibility or tolerance standards in screening trials.     

Effect of seed production location on the performance of Russet Burbank clones in southern Australia

In this study, three clones of Russet Burbank were grown at five different seed production sites and one other clone was grown at three of these sites. Seed from these treatments was then evaluated at two commercial production sites, in Victoria and Tasmania. Production site had a significant effect on the subsequent performance. Plant establishment, vigor, maturity, and stem and tuber number per plant were influenced by seed production site. Seed from more southerly locations had increased plant emergence, greater early vigor, earlier maturity, and reduced stem and tuber numbers per plant. Differences between the Tasmanian, Ruen and Victorian Netted Gem clones were small and restricted to the numbers of stems and tubers produced, and some yield components. The Ballarat clone was late maturing and had a high total but low marketable yield due to high levels of oversized and misshapen tubers. However this clone also showed least dark end to the fried crisp. Interactions were detected between clone and seed production site but these have no practical significance.     

Resistance toPseudomonas solanacearum in potato: Infectivity titrations in relation to multiplication and spread of the pathogen

When several wilt-resistant potato clones were tested against a highly virulent strain from Mexico (No. 276) by standard stem inoculation methods, only one clone ofSolanum phureja was resistant. When different inoculum concentrations were introduced quantitatively for infectivity titrations, however, different levels of resistance were clearly defined among clones previously rated as susceptible. Linear regression was used to estimate the ED₅₀ values (dosage required to wilt 50% of the population) for each of seven clones. These values ranged from 3 and 100 colony-forming units (CFU) for Katahdin and Russet Burbank, respectively, to 2.1 x 10⁶ CFU for S.phureja clone 1386.15. The distribution of bacteria in stems of Russet Burbank plants inoculated with the compatible strains 276 and K-60 and the incompatible strains B1 and S-210 was very different. In all cases, incompatible bacteria were not detected 10 cm above the inoculation point in the stem, even by 12 days after inoculation, whereas compatible strains multiplied rapidly at this site by 6 days. At the inoculation site and at sites immediately adjacent to it, however, incompatible bacteria attained populations that only differed by one order of magnitude from those of compatible bacteria. Similar results were obtained when a resistant clone (MS 118.24) was inoculated with the virulent strain K-60. Thus, resistance was characterized both by reduced acropetal spread and by tolerance to large numbers of the bacterium.     

腰果叶片氮磷钾年周期变化及再吸收效率

以6龄腰果无性系FL30为对象,采集全年12个月腰果成熟叶片样品,分析腰果叶片N、P、K年周期变化规律;并采集腰果衰老叶片样品,分析腰果树N、P、K再吸收效率.结果表明:腰果叶片N、P、K含量随生育期的改变而变化;叶片N含量从抽梢期至果实成熟呈上升趋势,果实成熟后明显下降,休眠期叶片N含量变化不大;叶片P含量从抽梢期至初果期总体呈下降趋势,初果期至休眠期则呈上升趋势；叶片N/P呈现出与N相似的年周期变化规律;叶片K含量在抽梢期呈下降趋势,初花期骤然上升,盛花坐果期继续缓慢上升,果实生长期至休眠期则呈下降趋势;腰果成熟叶片N、P、K含量显著高于衰老叶片,N、P、K再吸收率较高,再吸收效率顺序为REp＞REN＞REk.     

育苗措施对橡胶树小苗芽接苗生长的影响

为了探明育苗措施对橡胶树小苗芽接苗生长的影响,以不同时段播种的‘GT1’实生苗为砧木,‘云研77-4’‘云研77-2’‘GT1’为接穗,通过统计芽接成活率、抽芽率、苗木的茎粗和苗高4个指标,结合隶属函数值法系统地评价了育苗措施对橡胶树小苗芽接苗生长的影响。结果表明：（1）砧木播种时间对3个品种的芽接成活率及生长量的影响效应达显著或极显著水平,对抽芽率无显著影响,最佳播种时间在3个品种间存在差异,‘云研77-4’和‘云研77-2’在当年10月中旬播种最好,综合评价值分别为2.33和2.30,‘GT1’在次年1月初播种较好,综合评价值为2.32;（2）砧木月龄对3个品种的芽接成活率的影响达极显著水平,而对其他3个指标的影响不显著,最佳月龄在3个品种中表现一致,均表现为籽苗移栽60 d时的芽接效果最好;（3）锯砧方式对3个品种的抽芽率和苗高有显著或极显著的影响,而对芽接成活率和茎粗（‘GT1’除外）的影响不显著,最佳锯砧方式在3个品种中表现一致,均为先折砧后锯砧的处理方式最好。     

油茶无性系扦插育苗成效研究

[目的]探寻油茶无性系扦插育苗与保留不同叶面积的关系。【方法】采用随机区组设计法对油茶不同无性系扦插育苗与保留不同叶面积之间的关系进行研究。【结果】3个油茶无性系、4个处理扦插育苗当年成活率在74．1％-86．3％之间,其中A,B1处理扦插成活率较高,达86.3％;各处理扦插苗当年抽梢率和抽梢高度均低,3个油茶无性系、4个处理扦插苗抽梢率和抽梢高度分别仅0．4％～3．2％和1．2—2．3cm。[结论]油茶无性系扦插育苗宜选择B,处理．即1片叶子保留1／2叶片面积。     

Multiplication ofPseudomonas solanacearum in resistant potato plants and the establishment of latent infections

When 1-mo-old plants of a wilt-resistant clone ofSolanum phureja (1386.15) were stem-inoculated with three strains ofPseudomonas solanacearum (K60, S123, and S206), the bacteria multiplied rapidly at the point of inoculation and then moved in the vascular system to other parts of the stem. Resistant plants showed a remarkable ability to support relatively high populations of the bacterium in the absence of disease symptoms. Although multiplication in this resistant clone was substantially less than in susceptible Russet Burbank potato plants, large numbers of bacteria (up to 624 × 10⁴ cells of K60 per 5-cm stem segment) reached the base of the stem of plants maintained at high temperature (28°C) for 20 days after stem inoculation. From the base of the stem, the bacteria moved rapidly into the roots and tubers. Strains ofP. solanacearum differed in their ability to cause latent tuber infection in different resistant potato clones. When 11S.phureja ×S. tuberosum hybrids were stem-inoculated, maintained at 28°C for 3 wk and then grown to maturity at 20°C., most of the clones yielded tubers infected by one or more strains. The race 1 strain (K60) was the most infectious; 53.8% of all tubers harvested from all plants inoculated with this isolate carried latent infections. Because one clone (BR 53.1) never yielded infected tubers, there appear to be genetic factors which may be useful in breeding programs aimed at eliminating latent tuber infection.