利用秋水仙素喷淋加倍不同遗传基础的单倍体子粒探讨

以不同血缘及不同世代的遗传育种材料为母本、高频孤雌生殖诱导系辽诱1和CAU5等为父本杂交诱导产生的单倍体子粒为实验材料,研究秋水仙素浓度为0.625 mg/mL的条件下,用喷淋加倍设备对试验材料进行8 h喷淋的加倍效果。结果表明,喷淋秋水仙素后,郑单958的S2代的材料加倍率最高,为33.75%;第2位的是L3258×H71,是NSS种质S0代材料,其加倍率为13.02%;第3位的是D299/PH4CV,为NSS种质S1代材料,加倍率为10.34%。研究表明,喷淋秋水仙素的加倍效果与遗传背景关系紧密,喷淋秋水仙素加倍率总体由高到低的顺序为郑单958NSS种质(SS+NSS)种质SS种质欧洲杂交种,喷淋秋水仙素对全部试验材料的加倍率都有提高作用,比自然加倍提高0.83～5.08倍。利用该喷淋设备加倍单倍体子粒,具有节约用药量、操作简便、便于大规模生产应用、减少人员对秋水仙素的接触、废液回收方便、有利于保护环境等优点。     

农业科研基地科普工作的思考

国家高度重视科学普及工作,致力于不断提升公众科学文化素质。作为科普教育的重要组成部分,农业科研基地科普工作对加快推进农业现代化,助力乡村振兴发挥着不可替代的作用。文章阐述了农业科研基地在农业科普工作中的重要地位与作用,剖析了当前农业科研基地科普工作存在的主要问题,并针对这些问题提出了深入推动农业科普工作的对策建议。     

Using fishers' anecdotes, naturalists' observations and grey literature to reassess marine species at risk: the case of the Gulf grouper in the Gulf of California, Mexico

Designing fishing policies without knowledge of past levels of target species abundance is a dangerous omission for fisheries management. However, as fisheries monitoring started long after exploitation of many species began, this is a difficult issue to address. Here we show how the ‘shifting baseline’ syndrome can affect the stock assessment of a vulnerable species by masking real population trends and thereby put marine animals at serious risk. Current fishery data suggest that landings of the large Gulf grouper (Mycteroperca jordani, Serranidae) are increasing in the Gulf of California. However, reviews of historical evidence, naturalists’ observations and a systematic documentation of fishers’ perceptions of trends in the abundance of this species indicate that it has dramatically declined. The heyday for the Gulf grouper fishery occurred prior to the 1970s, after which abundance dropped rapidly, probably falling to a few percent of former numbers. This decline happened long before fishery statistics were formally developed. We use the case of the Gulf grouper to illustrate how other vulnerable tropical and semi‐tropical fish and shellfish species around the world may be facing the same fate as the Gulf grouper. In accordance with other recent studies, we recommend using historical tools as part of a broad data‐gathering approach to assess the conservation status of marine species that are vulnerable to over‐exploitation.     

Dopamine modulates the physiological response of the tiger shrimp Penaeus monodon

Levels of glucose, lactate, pO₂, pCO₂, HCO₃⁻, TCO₂, Na⁺, K⁺, Cl⁻, protein, and oxyhemocyanin in the hemolymph and its osmolality and pH were measured when tiger shrimp, Penaeus monodon (13.5 ± 1.5 g body weight), were individually injected with saline or dopamine at 10^− 8, 10^− 7, or 10^− 6 mol shrimp^− 1. Results showed that hemolymph glucose, lactate, pCO₂, HCO₃⁻, and TCO₂ values increased from 2 to 4 h; hemolymph osmolality, Na⁺, and total protein had increased at 2 h; and hemolymph K⁺ decreased from 2 to 8 h after the dopamine injection. All physiological parameters returned to the control values 4–16 h after receiving dopamine. The dopamine injection also significantly decreased the oxyhemocyanin/protein ratio of P. monodon which occurred at 2 h, resulting from an elevation of hemolymph protein and a slight decrease of oxyhemocyanin. These results suggest that stress-inducing dopamine caused a transient period of modulation of energy metabolism, osmoregulation, respiration, and the acid–base balance in P. monodon in adapting to this environmental stress.     

基于倍四元数和Groebner基的6R机械手的位置反解

提出了一般6R机械手的位置反解的新算法,该算法是把齐次变换矩阵转以倍四元数形式表示,建立了倍四元数形式的串联6R机械手运动学方程,再通过线性消元和两次应用分次字典序Groebner基消去5个变元,得到一个一元16次方程.此方法没有增根,是一种对空间任意尺寸6R机械手进行建模和求解的新算法.其中求解Groebner基采用了计算机代数系统进行有理数运算,目前的求解速度尚不是很高,需进一步改进.     

氮肥运筹模式对冬小麦氮素吸收利用的影响

为给小麦高产、高效、无污染及可持续生产提供合理的氮肥运筹技术和理论依据, 以烟农19为材料,在大田条件下,研究了不同施氮量和基追比例对土壤小麦系统氮素积累及分配的影响。结果表明,施氮可提高0~100 cm土体内的全氮含量。在小麦越冬前, 0~40 cm土层中NO3-N含量随氮肥用量和基肥比例的增加显著增加;起身期到拔节期,施氮量为180和240 kg·hm-2且基肥∶拔节肥∶孕穗肥为3∶5∶2处理的0~40 cm土层内NO3-N含量下降,而施氮量为240 kg·hm-2且基肥∶拔节肥为7∶3和5∶5的处理及施氮量为300 kg·hm-2且基肥∶拔节肥为7∶3的处理则显著增加;拔节期到成熟期,随施氮量的增加,0~60 cm土层速效氮增加幅度有所提高。孕穗肥可明显提高灌浆期的植株全氮含量。因此,在240 kg·hm-2 施氮水平、基肥∶拔节肥∶孕穗肥为3∶5∶2条件下,施氮既能减少土壤硝态氮累积量,又能有效降低土壤硝态氮污染地下水的可能性。     

施肥量与氮肥基追比对西农979产量和品质的效应

为给小麦品种西农979的优质高产栽培提供理论依据,在高、中两种施肥量(高肥:每公顷施纯氮270kg、P2O5 225 kg、K2O 120 kg;中肥:每公顷施纯氮180 kg、P2O5 120 kg、K2O 120 kg)和氮肥7:3、6:4、5:3 :2、10:0四种基追比例(一次追氮在拔节期进行,两次追氮分别在拔节期与孕穗期进行)条件下,研究了施肥量和氮肥基追比例对西农979产量和品质的影响.结果表明,高肥处理产量比中肥处理产量提高9.66%;无论在中肥或高肥条件下,籽粒产量均随氮肥追施比例的增加而提高.施肥量和氮肥基追比例对千粒重的影响较小,对穗粒数的影响居中,对群体穗数的调控作用较大.氮肥基追并施可显著提高成穗率.随施肥量的提高和氮肥追施比例的加大,群体穗数逐渐增加,籽粒蛋白质含量和湿面筋含量也有逐渐提高的趋势,但蛋白质含量增幅小,湿面筋含量增幅大.高施肥量下,氮肥基追比例5:3:2,西农979的籽粒产量、蛋白质含量和湿面筋含量最高,分别达到8 573.5 kg·hm-2、14.97%和32.12%.     

水稻矮秆突变体Zj88d的鉴定与基因定位

 用甲基磺酸乙酯诱变处理常规粳稻浙粳88,获得了矮秆水稻突变体Zj88d,多代自交稳定遗传。遗传分析表明突变体Zj88d的矮秆性状受一对隐性核基因控制。采用图位克隆方法,将目的基因定位在水稻第7染色体短臂末端7 44w和RM5344间的603 kb区间。排查该区间包含的100个候选基因,发现已克隆的矮秆基因OSH15也位于其中。测序结果显示,突变体Zj88d中的OSH15基因在第2内含子最末位发生“g→a”单碱基突变。     

Relationship Between the First Base of the Donor Splice Site of Waxy Gene Intron 1 and Amylose Content in Yunnan Indigenous Rice Varieties

There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT-genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content (18.95% on average) than those with TT-genotype (all below 16%), but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 (P<0.01).     

云南省甘蔗收获机械推广难点及策略分析

根据云南省推广甘蔗收获机械的实际情况,从农户层面探究推广中存在的主要问题,分析宣传推广效果不佳的具体原因,从多个角度提出增强推广应用效果的可行性建议,为促进甘蔗收获机械在云南地区的应用提供参考。