草莓产区种苗生产问题调研分析——以江苏省东海县草莓产区为例

近年草莓种苗质量问题越来越受到行业内的重视,在一些种植年限久、规模大的种植区内尤为明显。本文通过对江苏省东海县草莓产区考察调研,了解近年生产苗使用状况,并对育苗过程中存在的主要问题及原因进行了分析。结果显示,当地外购生产苗占相当比例且来源地广泛,受苗木质量等问题影响,近年首批生产苗定植成活率明显下降;夏季育苗成功率较低,种苗退化及病害问题较为突出,育苗田状况、苗期管理技术等需要进一步提升。文章从保障优质种苗供应、规范提升育苗方法及加强育苗组织化程度等方面提出了相关具体意见措施,以为改善草莓种苗生产供应状况提供参考。     

铁皮石斛林下培育技术研究

分析了铁皮石斛的培育技术,采用选优繁殖、扦插等技术,其苗木生长迅速。结果显示：铁皮石斛用1年、2年生的嫩枝扦插,在立春季节扦插培育较适宜,幼苗生长良好。用植物激素处理扦插,植物激素能促进铁皮石斛扦插穗条生根、萌芽、抽稍,苗木生长快。尤其植物细胞分裂素又能对铁皮石斛扦插穗条抽芽产生较大的良好生长效果。     

木本油料树种良种选育工作势在必行

良种是生产力发展的基础性、战略性资源,是可持续发展的重要物质基础,是实现优质丰产、增产增收的先决条件.笔者从推动宜昌木本油料产业健康发展的角度,阐述了加强宜昌木本油料良种选育的重要性、必要性和方法.     

Resistance to Streptococcus iniae and its genetic associations with traits of economic importance in Asian seabass (Lates calcarifer)

Streptococcus iniae is one of the most serious aquatic pathogens, causing significant economic losses in marine and freshwater species, including Asian seabass (Lates calcarifer). Controlling this gram‐positive bacterial pathogen has been an issue in aquaculture systems, due to the combined effects of aquaculture intensification and climatic impacts. To date, there have not been any genetic parameter estimates for S. iniae resistance in Asian seabass. The main aim of this study was to examine genetic variation in S. iniae resistance and its genetic correlations with growth and cannibalism in Asian seabass families produced from a breeding programme for high growth in 2016 and 2017. The study included a total of 5,835 individual fish that were offspring of 41 sires and 60 dams (31 half‐sib and 34 full‐sib families). The experimental fish were challenged by intraperitoneal injection with a volume containing 10⁵ CFU (colony‐forming unit)/fish. Resistance to S. iniae was measured as survival rate at 6 hr, 3, 5, 7, 10 and 15 days post‐challenge test. There were significant variations in S. iniae resistance among families at different observation periods (ranging from 24.4% to 80%). Restricted maximum‐likelihood method and mixed model analysis were applied to estimate heritability for S. iniae resistance. The heritability for S. iniae resistance ranged from 7% to 18% across different statistical models used. The common full‐sib effects accounted for 0.1%–2% of the total variation in resistance to S. iniae. Genetic correlations of the S. iniae resistance at 6 hr and 3 days with later post‐challenge test periods were low to moderate. However, these estimates for S. iniae resistance between successive measurement times (5, 7, 10 and 15 days) were high and close to 1. The genetic correlations of resistance with body weights at 180, 270 and 360 days post‐hatch were not significant as well with cannibalism. It is concluded that there is substantial additive genetic variation in resistance to S. iniae, suggesting there is potential for genetic improvement of Asian seabass for resistance to S. iniae through selective breeding.     

The Identification of QTL Associated with Cotton Fruit Branch Length Suitable for Mechanized Harvest Utilizing BSA-seq

[Objective] This study aims to identify quantitative trait loci (QTLs) associated with cotton fruit branch length by using the combination of bulked-segregant analysis (BSA) and next-generation sequencing (NGS) method. [Method] In this study, the cotton F₂ segregating population was developed with the short branch line Sujimian 125 and long-branch variety Sikang 1 as cross parents. According to the average internode length of fruit branches in middle, extreme individuals in F₂ population were divided into two groups to generate the bulked DNA samples. The whole-genome resequencing of two DNA bulks was applied to analyze the single nucleotide polymorphism (SNP) and insertion-deletion (InDel) between two groups, and the fruit branch internode length related QTLs were detected using Euclidean distance (ED). [Result] With SNP data obtained from sequencing, a 0.8 Mbp range associated region on chromosome A3 was identified; with InDel data obtained from sequencing, a 1.09 Mbp range associated region on chromosome A3 was identified. Two regions overlapped, and the overlapped range was 0.77 Mbp. [Conclusion] This result suggested that the difference between I-type fruit branch and zero-type was due to different genetic locus and pattern rather than dosage effect of the same gene.     

糯玉米新品种河糯612的选育及高产栽培技术

河糯612是以自交系 HN601作为父本，与自主选择自交系 HN16作为母本，经杂交选育而成的糯玉米杂交种，于2018年5月30日通过广西壮族自治区农作物品种审定委员会审定。河糯612幼苗长势旺盛、整齐，植株穗位、株高较为整齐，果穗均匀、穗长较长，结实好，行排列整齐，行间紧致，出籽率比较高，色泽好。可在广西全区种植。     

过氧化氢和甲醛对SPF级大鼠和小鼠繁殖室消毒效果观察

目的比较观察过氧化氢和甲醛对SPF级大鼠和小鼠繁殖室内表面、台面以及空气的消毒效果,选择消毒效果良好的消毒剂。方法采用空气落下菌检测法和表面细菌拭子检测法,对过氧化氢和甲醛熏蒸SPF级大鼠和小鼠繁殖室的消毒效果进行检测观察。结果SPF级大鼠和小鼠繁殖室分别经过氧化氢和甲醛熏蒸消毒后,进行空气落下菌的检测,过氧化氢和甲醛对大鼠繁殖室和小鼠繁殖室空气的杀菌率分别为100%、97.5%和100%、100%;将墙壁、地面和笼架表面的菌落数进行检测,过氧化氢和甲醛对大鼠繁殖室墙壁、地面和笼架的杀菌率分别为100%、99%、100%和95%、100%、99%,对小鼠繁殖室墙壁、地面和笼架的杀菌率均为100%。结论过氧化氢蒸汽消毒是比较理想的消毒方法,很好地控制了SPF级大鼠和小鼠繁殖室环境微生物,安全性高且消毒效果明显。     

The role of ear environment in postharvest susceptibility of maize to toxigenic Aspergillus flavus

A kernel screening assay (KSA) was used to assess the genetic and environmental effects on the vulnerability of maize to aflatoxin accumulation. Kernels of 26 inbred lines that had been grown in seven environments, and 190 lines of the Intermated B73xMo17 (IBM) population grown in one location in the United States, were inoculated with a toxigenic strain of A. flavus and incubated in the dark at 30°C for 6 days. Percent kernel colonization (PKC), sporulation and aflatoxin were influenced by the maize genotypes (G), the location (“ear environment” or E) and the GxE interactions. Overall, low broad‐sense heritabilities were observed for PKC, sporulation and aflatoxin. PKC was significantly correlated with sporulation in all environments. Aflatoxin was positively correlated with colonization for two and with sporulation for all ear environments. Higher grain sulphur or magnesium in IBM was associated with less colonization or aflatoxin. Postharvest susceptibility of maize to aflatoxin is thus influenced by factors that are modulated by the ear environment. In a KSA, sporulation could be a proxy test for aflatoxin accumulation.     

Increasing pre‐acclimation temperature reduces the freezing tolerance of winter‐type faba bean (Vicia faba L.)

Autumn‐sown winter‐type faba bean (Vicia faba L.) has been shown to have a yield advantage over spring sowing. Still, adoption of this overwintered pulse crop remains limited in temperate locations, due to inadequate winter hardiness. This research sought to understand how the prevailing temperature during emergence and seedling development, that is pre‐acclimation, influences freezing tolerance. Seedlings grown under a controlled “warm” 17/12°C (day/night) pre‐acclimation environment were initially less freezing tolerant than those grown under a “cold” 12/5°C temperature treatment. Stem and particularly root tissues were primarily responsible for slower cold acclimation, and there was a genotype specific response of above‐ground tissues to pre‐acclimation treatment. Both above and below‐ground tissues should be tested across a range of pre‐acclimation temperatures when screening faba bean germplasm for freezing tolerance.     

高海拔地区农牧民收入调查报告

为了解高海拔农牧民收入状况，2009—2014 年通过实地走访，对西藏自治区拉萨市当雄县郭庆村179 户牧民进行跟踪调查，调查内容包括当雄县郭庆村牧民牲畜养殖情况、家庭劳动力人数及人均年收入等。结果表明，整体上牧民收入和牲畜存栏量在不断增加，但从人均可支配收入的分布可知中低收入群体占比较重。根据这些收入现状问题，提出促进草原畜牧业的提质增效以及增加低收入人群的劳动就业率等建议。