In vitro morphogenesis of juvenile Annona cherimola Mill,bud explants

A micropropagation procedure for juvenile cherimoya (Annona clierimola Mill.) is described. Axillary shoot proliferation was obtained after culturing nodal sections with lateral buds in basal medium supplemented with either 0.66 μM BA or 1,36μM zeatin. For root induction shoots were pre-incubated for 7 d in basal medium supplemented with 1 gl^?1 activated charcoal, then cultured for 10 d (7 dark/3 light) on medium with 500 μM IBA, 58.4 mM sucrose, and 200 mg I“1 citric acid. Afterwards, shoots were transferred to the same medium without auxin and with the macroelements at half strength. Using this procedure, 95% of shoots rooted. The survival rate at the end of the acclimatization period was 70%.     

Natural hybridization between wheat (Triticum aestivum L.) and its wild relatives Aegilops geniculata Roth and Aegilops triuncialis L.

BACKGROUND

Cultivated bread wheat (Triticum aestivum L.) spontaneously hybridizes with wild/weedy related Aegilops populations, but little is known about the actual rates at which this hybridization occurs under field conditions. It is very important to provide reliable empirical data on this phenomenon in order to assess the potential crop–wild introgression, especially in the context of conducting risk assessments for the commercialization of genetically modified (GM) wheat, as gene flow from wheat to Aegilops species could transfer into the wild species genes coding for traits such as resistance to herbicides, insects, diseases or environmental stresses.

RESULTS

The spontaneous hybridization rates between wheat and A. geniculata and A. triuncialis, which are very abundant in the Mediterranean area, have been estimated for the first time in the northern part of the Meseta Central, the great central plateau which includes the largest area of wheat cultivation in Spain. Hybridization rates averaged 0.12% and 0.008% for A. geniculata and A. triuncialis, respectively. Hybrids were found in 26% of A. geniculata and 5% of A. triuncialis populations, at rates that can be ≤3.6% for A. geniculata and 0.24% for A. triuncialis.

CONCLUSION

The detection of Aegilops spp.–wheat hybrids in Aegilops populations indicates that gene flow can occur, although wheat is considered a crop with a low-to-medium risk for transgene escape. These data on field hybridization rates are essential for GM wheat risk assessment purposes. © 2023 Society of Chemical Industry.     

始丰微型牛体型与外周血cAMP、PTH和TGF-β水平关联性分析

为阐明始丰微型牛的生长发育相关的生化特性,采用ELISA方法对15月龄的始丰微型牛和作对照的正常体型天台黄牛测定并比较分析外周血中三个生长发育相关因子:cAMP、PTH与TGF-β.结果表明:微型牛组TGF-β含量(192.6 ng/L)极显著低于对照组(229.5 ng/L)(P＜0.01),cAMP和PTH含量与对...     

反刍动物脂类营养研究进展

反刍动物日粮中脂类的含量较低,精料中含2％～4％,粗料中含5％～7％。在常规日粮中,脂类大部分是以甘油三酯的形式存在,另外还有小部分的糖脂和角质脂（主要是蜡质和复合脂）。饲草中脂类主要是复合脂,包括糖脂和磷脂（70％～80％）。     

Hydraulic Retention Time Influence on Improving Flocculation in the Activated Sludge Processes Through Polyelectrolytes

Hydraulic retention time (HRT) influence improving sludge flocculation with adding the polyelectrolytes (non-ionic, anionic, and cationic) was studied on an activated sludge (AS) system fed with synthetic domestic wastewater (SDW), dairy industry wastewater (DIW), and caramel industry wastewater (CIW). The sludge volumetric index, food/microorganism ratio (F/M), and mixed liquor volatile suspended solids at different HRTs (6, 8 and 10 h) were monitored on an experimental model. Results showed that both SDW and IW had the best sludge flocculation conditions at 8 h and 100 mL of non-ionic polyelectrolyte (0.2 mg L^?1). In addition, this phenomenon reached the organic matter removal efficiencies of 95.9, 95.7, and 94.2% for SDW, DIW, and CIW, respectively. Therefore, optimum HRT increased the organic matter removal efficiencies by 10%, sludge concentration by 37% (22–55%), and F/M ratio by 70%. Moreover, the polyelectrolytes used in AS improved the sludge flocculation by 2.9 times.     

甘蓝EST-SSR标记的开发与应用

从NCBI数据库下载62567条甘蓝相关EST,处理后得到19611条无冗余的EST,对其进行SSR搜索,共得到1219条SSR,分布在1176条EST上,分布密度为1/11.48kb,包括273种重复基元。在甘蓝EST-SSR中,二核苷酸(353个SSR)和三核苷酸(423个SSR)占主导地位,所占比例分别为28.96%和34.70%;出现最多的重复基元是AG/CT,占总数的25.59%,其次为AAG/CTT(94个,占7.71%)。针对1176条含有SSR的EST设计合成了978对引物。用两份甘蓝自交系对978对引物进行初筛,897对引物有扩增产物,共扩增出1026条扩增带;128对引物表现出多态性,共有258条多态性带(占总带数的25.15%)。利用4对多态性引物,初步构建了中甘11、8398、中甘15、中甘21杂交新品种及其亲本的指纹图谱。以上结果说明从甘蓝相关EST数据库中开发的SSR引物有较好的可用性。     

Effects of intensification of pastoral farming on greenhouse gas emissions in New Zealand

Abstract

AIMS: The aims of this cross-sectional study were to investigate the herd and cow-level prevalence of bovine digital dermatitis (BDD) in dairy farms in the northern Taranaki region of New Zealand, and to identify whether there was any spatial clustering of herds with the disease.

METHODS: A survey of 224 dairy farms in the northern Taranaki region of New Zealand was undertaken from September 2014 to February 2015. Following training in robust criteria to confirm BDD visually, a technician inspected the rear feet of every milking cow on the farms during milking. The identity of cows with lesions and the feet involved were recorded. The proportion of cows affected among the inspected population (cow-level prevalence), the proportion of a herd affected (farm-level prevalence), and proportion of farms with ≥1 cow with lesions, were calculated. A bivariate K function analysis was then used to assess whether farms with ≥1 cow with lesions were clustered, after accounting for the distribution of the farms involved in the study.

RESULTS: Bovine digital dermatitis lesions were observed on 143/224 (63.8 (95% CI=57.5–70.1)%) farms. Within-farm prevalence was 0% on 81 (36.2%) farms, between >0 and <3% on 120 (53.5%) farms, with a maximum prevalence of 12.7% on one farm. Overall, cow-level prevalence was 707/60,455 (1.2 (95% CI=0.9–3.0)%), and on affected farms was 707/41,116 (1.7 (95% CI=1.4–2.1)%). In affected cows, 268/707 (37.9%) had a lesion on left foot only, 262/707 (37.1%) on the right foot only and 177/707 (25.0%) on both feet. The K function analysis showed no evidence of clustering of farms with BDD.

CONCLUSIONS: Bovine digital dermatitis was widespread among the survey farms, but there was no evidence that there was any clustering of herds with BDD. The cow-level prevalence on affected farms was much lower than reported elsewhere.

CLINICAL RELEVANCE: Although the prevalence at the cow level was low, if these data are representative of other regions of New Zealand, BDD could easily become a major problem on dairy farms in New Zealand, as has been observed in other countries.     

木酢液对3种叶菜产量和品质的影响

木酢液是在烧制木炭过程中木材热解成分的冷凝回收液,具有特殊的烟熏气味,呈酸性,淡黄色至红褐色,组成成分相当复杂,含有200多种小分子有机成分,主要是有机酸、酚类、酮类、醇类和酯类,其中以醋酸为主要成分,占有机成分的50％左右。木酢液在美国、日本、韩国等国的农业生产中均有应用。在美国,木酢液主要应用于花园园艺;     

Fertility of Holstein cows and heifers submitted to timed artificial insemination and receiving one or two doses (12 h apart) of semen

The objective of this retrospective study was to assess the effect of receiving a single (n = 50,285) or double (n = 4392) artificial insemination (AI), 12 h apart, within a timed artificial insemination protocol on pregnancy per AI (P/AI) in nulliparous heifers (inseminated with either sex-sorted or conventional semen) and pluriparous Holstein cows in a commercial dairy herd. Also, this study aimed to investigate the relationship between temperature-humidity index (THI) and time of the first AI and fertility. Fertility of cows receiving two AI with normothermia (THI <68) was higher (p < .05) than cows receiving a single AI (42.9% vs. 36.4%). P/AI of cows receiving two AI with severe heat stress (THI >85) was higher (p < .05) than cows receiving a single AI (21.0% vs. 12.6%). Regardless of heat stress conditions, applying the first AI in the morning increased (p < .05) P/AI in cows with double AI than in cows whose first AI occurred in the afternoon (38.4 vs. 33.3%). With moderate heat stress, and sexed-sorted semen, P/AI to timed AI was higher (65.0 vs. 51.9%; p < .05) in heifers receiving double AI than those serviced once. It was concluded that double AI, 12 h apart, enhanced fertility at timed AI than herd mates with a single AI, particularly with heat stress at breeding.