Background and Research Prospect of Geo-ecological Survey and Monitor in the Critical Zone of Black Soil

The American Science journal,on the occasion of its 125 publication anniversary,in 2016,released 125 of the most challenging scientific issues(Kennedy et al.,2005)to the world.According to the basics,breadth and the influence,25 of the issues which considered to be the most important were screened,including"How many people can the Earth carry?"(Stokstad,2005;Dailyg et al.,1992;Cohen,1995)and"How high will the greenhouse effect make the earth temperature?

Improved maceration techniques to study the fruit vascular anatomy of grape

The visualization and evaluation of fruit vascular bundles in grape are indispensable for understanding the development and growth of the fruit. The vascular bundles in grape are as thin as human hair, and strongly adhere to flesh cells, making it difficult to isolate individual intact vessel elements. Currently there is little information about methods to characterize grape vascular tissue. In this study, we describe an easy and effective technique to visualize the xylem cell structure of the ‘Red Globe' grape(Vitis L.). The intact vascular bundles of the grape were isolated through enzymatic degradation of flesh cells by hydrolases which were effective in removing flesh cells from vascular bundles. This enabled the illustration of the fine surface structure of vessel elements and their arrangement in the vascular bundles of the grape. This modified method to separate the vascular bundles into individual vessel elements was more effective than former methods of manually shaking to isolate individual vessels. Clear images of xylem vessel arrangement and structural characteristics of individual vessel element were acquired by light microscopy(BX51, Olympus, Tokyo, Japan), transmission electron microscopy(Tecnai 12, Philips, Netherlands) and scanning electron microscopy(GeminiSEM 300, Carl Zeiss, Germany). In addition, the 3D structure of vessel elements was observed using confocal laser scanning microscopy(Zeiss: model: LSM-880, Oberkochen, Germany). The imaging techniques for visualizing and analyzing the structure of xylem vessels in grape described in this study are an improvement of past methods. An effective method to isolate grape vascular bundles from flesh cells was also developed, which enables the imaging of the fine surface structure of vessel elements and their arrangement in grape vascular bundles. By adjusting the process of maceration of vascular bundles, an easy and effective method was developed to gently disrupt the plant tissue and isolate individual vessel elements. These improved techniques are suitable to observe the intact morphology of vascular bundles in the grape, improve experimental efficiency and accelerate new discoveries on the anatomical structure of the grape.

Genome-wide association studies in apple reveal loci of large effect controlling apple polyphenols

Apples are a nutritious food source with significant amounts of polyphenols that contribute to human health and wellbeing,primarily as dietary antioxidants.Although numerous pre-and post-harvest factors can affect the composition of polyphenols in apples,genetics is presumed to play a major role because polyphenol concentration varies dramatically among apple cultivars.Here we investigated the genetic architecture of apple polyphenols by combining high performance liquid chromatography(HPLC)data with~100,000 single nucleotide polymorphisms(SNPs)from two diverse apple populations.We found that polyphenols can vary in concentration by up to two orders of magnitude across cultivars,and that this dramatic variation was often predictable using genetic markers and frequently controlled by a small number of large effect genetic loci.Using GWAS,we identified candidate genes for the production of quercitrin,epicatechin,catechin,chlorogenic acid,4-O-caffeoylquinic acid and procyanidins B1,B2,and C1.Our observation that a relatively simple genetic architecture underlies the dramatic variation of key polyphenols in apples suggests that breeders may be able to improve the nutritional value of apples through markerassisted breeding or gene editing.