scholarly journals Sugarcane Ratooning Ability: Research Status, Shortcomings, and Prospects

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1052
Author(s):  
Fu Xu ◽  
Zhoutao Wang ◽  
Guilong Lu ◽  
Rensen Zeng ◽  
Youxiong Que

Sugarcane is an important sugar crop and it can be subjected to ratooning for several years. The advantages of ratooning include quality improvement, efficiency enhancement, and reduced costs and energy use. The genotype, environment, cultivation management, and harvesting technology affect the productivity and longevity of ratoon cane, with the genetic basis being the most critical factor. However, the majority of research has been focused on only limited genotypes, and a few studies have evaluated up to 100 sugarcane germplasm resources. They mainly focus on the comparison among different genotypes or among plant cane, different selection strategies for the first and second ratoon crops, together with screening indicators for the selection of stronger ratooning ability. In this paper, previous studies are reviewed in order to analyze the importance of sugarcane ratooning, the indicative traits used to evaluate ratooning ability, the major factors influencing the productivity and longevity of ratooning, the genetic basis of variation in ratooning ability, and the underlying mechanisms. Furthermore, the shortcomings of the existing research on sugarcane ratooning are highlighted. We then discuss the focus of future ratoon sugarcane research and the technical methods that will shorten the selection cycle and increase the genetic gain of ratooning ability, particularly the development of linked markers. This review is expected to provide a reference for understanding the mechanisms underlying the formation of ratooning ability and for breeding sugarcane varieties with a strong ratooning ability.

2021 ◽  
Vol 174 (1) ◽  
Author(s):  
Amirlan Seksenbayev

AbstractWe study two closely related problems in the online selection of increasing subsequence. In the first problem, introduced by Samuels and Steele (Ann. Probab. 9(6):937–947, 1981), the objective is to maximise the length of a subsequence selected by a nonanticipating strategy from a random sample of given size $n$ n . In the dual problem, recently studied by Arlotto et al. (Random Struct. Algorithms 49:235–252, 2016), the objective is to minimise the expected time needed to choose an increasing subsequence of given length $k$ k from a sequence of infinite length. Developing a method based on the monotonicity of the dynamic programming equation, we derive the two-term asymptotic expansions for the optimal values, with $O(1)$ O ( 1 ) remainder in the first problem and $O(k)$ O ( k ) in the second. Settling a conjecture in Arlotto et al. (Random Struct. Algorithms 52:41–53, 2018), we also design selection strategies to achieve optimality within these bounds, that are, in a sense, best possible.


2021 ◽  
Vol 13 (8) ◽  
pp. 4441
Author(s):  
Sharif Shofirun Sharif Ali ◽  
Muhammad Rizal Razman ◽  
Azahan Awang ◽  
M. R. M. Asyraf ◽  
M. R. Ishak ◽  
...  

Despite growing urban electricity consumption, information on actual energy use in the household sector is still limited and causal factors leading to electricity consumption remain speculative due to urban expansion and its growing complexity, particularly in developing countries such as Malaysia. This study aims to examine the critical determinants of household electricity consumption by evaluating the patterns and flows of consumption and analysing relationships and their effects on electricity usage among 620 urban households in Seremban, Malaysia. Results suggest that the average urban household electricity consumption is 648.31 kWh/month; this value continues to grow with the increase in the household monthly income (r = 0.360; p < 0.01) and number of rooms (r = 0.360; p < 0.01) as quality of life improves. A large portion of electricity is allocated for kitchen/home consumption, followed by cooling and lighting. Multiple linear regressions revealed that married households with a high monthly income and living in spacious houses together with three to five people are important predictors of electricity consumption in Seremban. This study empirically identified that the number of rooms is the most critical factor of electricity consumption and strategies to increase energy efficiency, maintain resource sustainability and minimise greenhouse gas threat on the urban ecosystem are vital. Therefore, promoting low carbon initiatives for energy conservation and technology improvement and implementing policies in the domestic sector are essential to achieve the greatest potential energy consumption reduction in urban regions.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jianyu Meng ◽  
Xingjiang Chen ◽  
Changyu Zhang

Abstract Myzus persicae is a serious and widespread agricultural pest, against which, imidacloprid remains an effective control measure. However, recent reports indicate that this aphid has evolved and developed resistance to imidacloprid. This study aimed to elucidate the underlying mechanisms and genetic basis of this resistance by conducting comparative transcriptomics studies on both imidacloprid-resistant (IR) and imidacloprid-susceptible (IS) M. persicae. The comparative analysis identified 252 differentially expressed genes (DEGs) among the IR and IS M. persicae transcriptomes. These candidate genes included 160 and 92 genes that were down- and up-regulated, respectively, in the imidacloprid-resistant strain. Using functional classification in the GO and KEGG databases, 187 DEGs were assigned to 303 functional subcategories and 100 DEGs were classified into 45 pathway groups. Moreover, several genes were associated with known insecticide targets, cuticle, metabolic processes, and oxidative phosphorylation. Quantitative real-time PCR of 10 DEGs confirmed the trends observed in the RNA sequencing expression profiles. These findings provide a valuable basis for further investigation into the complicated mechanisms of imidacloprid resistance in M. persicae.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Huimin Wang ◽  
Junheng Liang ◽  
Qianwen Yue ◽  
Long Li ◽  
Yan Shi ◽  
...  

Abstract Background Polyketide synthases (PKSs) include ketone synthase (KS), acyltransferase (AT) and acyl carrier protein (ACP) domains to catalyse the elongation of polyketide chains. Some PKSs also contain ketoreductase (KR), dehydratase (DH) and enoylreductase (ER) domains as modification domains. Insertion, deletion or substitution of the catalytic domains may lead to the production of novel polyketide derivatives or to the accumulation of desired products. Epothilones are 16-membered macrolides that have been used as anticancer drugs. The substrate promiscuity of the module 4 AT domain of the epothilone PKS (EPOAT4) results in production of epothilone mixtures; substitution of this domain may change the ratios of epothilones. In addition, there are two dormant domains in module 9 of the epothilone PKS. Removing these redundant domains to generate a simpler and more efficient assembly line is a desirable goal. Results The substitution of module 4 drastically diminished the activity of epothilone PKS. However, with careful design of the KS-AT linker and the post-AT linker, replacing EPOAT4 with EPOAT2, EPOAT6, EPOAT7 or EPOAT8 (specifically incorporating methylmalonyl-CoA (MMCoA)) significantly increased the ratio of epothilone D (4) to epothilone C (3) (the highest ratio of 4:3 = 4.6:1), whereas the ratio of 4:3 in the parental strain Schlegelella brevitalea 104-1 was 1.4:1. We also obtained three strains by swapping EPOAT4 with EPOAT3, EPOAT5, or EPOAT9, which specifically incorporate malonyl-CoA (MCoA). These strains produced only epothilone C, and the yield was increased by a factor of 1.8 compared to that of parental strain 104-1. Furthermore, mutations of five residues in the AT domain identified Ser310 as the critical factor for MMCoA recognition in EPOAT4. Then, the mutation of His308 to valine or tyrosine combined with the mutation of Phe310 to serine further altered the product ratios. At the same time, we successfully deleted the inactive module 9 DH and ER domains and fused the ΨKR domain with the KR domain through an ~ 25-residue linker to generate a productive and simplified epothilone PKS. Conclusions These results suggested that the substitution and deletion of catalytic domains effectively produces desirable compounds and that selection of the linkers between domains is crucial for maintaining intact PKS catalytic activity.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 254-255
Author(s):  
Alexey V Shakhin ◽  
Arsen V Dotsev ◽  
Tatiana E Deniskova ◽  
Gottfried Brem ◽  
Natalia A Zinovieva

Abstract Prolificacy is a very important trait in sheep. Romanov sheep, the well-known Russian sheep breed, are characterized by very high prolificacy; however, the genetic basis of this unique property of Romanov sheep is still unknown. It was reported that Ovine BMPR1B gene, located on the OAR6, is associated with prolificacy in several sheep breeds. The aim of our study was to identify candidate SNPs within BMPR1B gene, related to prolificacy. To achieve this goal, using NGS technology, we sequenced ovine BMPR1B gene in Romanov sheep (n = 6), which are characterized by high prolificacy (about 270 lambs per 100 ewes). The sequences of BMPR1B gene of Noire du Velay, Tan, Southdown and Australian Horned Merino sheep breeds as well as Asiatic mouflon (n = 1), which are characterized by significantly lower prolificacy (from 110 to 180 lambs per 100 ewes) were derived from publicly available sources and used for comparison. FST analysis performed in PLINK 1.9 program revealed 10 SNPs with values higher than 0.8. The majority of candidate SNPs under putative selection were localized in the region from 29,382,098 to 29,430,387 on OAR6 of Ovine reference genome (Oar_v3.1 (Ensembl release 98). Thus, we can suggest, that this region of the BMPR1B gene can be considered as the putative region, associated with high prolificacy of Romanov sheep. Additional studies will be needed to confirm the effect of identified candidate SNPs on prolificacy traits. The research results will be useful for artificial selection of sheep with higher prolific capacity, including the introduction of desired alleles in sheep populations using genome editing technologies. This work was supported by the Russian Ministry of Science and Higher Education No. 0445-2019-0024 and RFBR No. 20-516-56002.


2009 ◽  
Vol 44 (11) ◽  
pp. 1452-1459 ◽  
Author(s):  
Aliny Simony Ribeiro ◽  
José Francisco Ferraz de Toledo ◽  
Magno Antonio Patto Ramalho

The objective of this work was to identify the best selection strategies for the more promising parental combinations to obtain lines with good resistance to soybean Asian rust (Phakopsora pachyrhizi). Two experiments were carried out in the field during the 2006/2007 and 2007/2008 growing seasons, to determine the percentage of infected leaf area of individual plants of five parents and their segregant F2 and F3 populations. The data obtained indicates that additive genetic variance predominates in the control of soybean resistance to Asian rust, and that the year and time of assessment do not significantly influence the estimates of the genetic parameters obtained. The narrow-sense heritability (h²r) ranged from 23.12 to 55.83%, and indicates the possibility of successful selection of resistant individuals in the early generations of the breeding program. All the procedures used to select the most promising populations to generate superior inbred lines for resistance to P. pachyrhizi presented similar results and identified the BR01-18437 x BRS 232 population as the best for inbred line selection.


2014 ◽  
Vol 21 (3) ◽  
pp. 301-326 ◽  
Author(s):  
Nicolas De Vijlder ◽  
Michael Limberger

Indebted cities were a widespread phenomenon during theAncien Régime. However, some found ways to innovate the management of their municipal debt, whilst others fell prey to over-indebtedness or default. In this article we have left the success stories aside and focused on the latter. Using early modern Antwerp as a case study, we have disentangled the underlying mechanisms that ultimately lead to over-indebtedness and (in some cases) default. Whilst the economic climate and the relationship between city and state have been rightly identified as major factors in the previous literature, our contribution brings another element to the table, namely, the inflexibility of long-established rent arrangements and the entanglement between the ruling elite and therentiers. We show that there was a strong overlap between both groups, which had a huge impact on the financial policy of cities during the early modern period.


2018 ◽  
Vol 7 (2) ◽  
pp. 125
Author(s):  
Agung Listiadi

Cost is an important factor in ensuring the company win in the competition on the market. Consumers will choose a manufacturer that is able to produce products and services that have high quality with low prices. Costs of Management Systems Contemporary emphasis on search than the allocation. And management based activities are at the heart of contemporary operating control system. At least two major factors that must be considered in the selection of cost driver (cost driver) are: the cost of measurement and the degree of correlation between the consumption cost driver with the actual overhead. Cost driver is divided into two categories, namely the structural cost driver and executional cost driver. Cost driver is the basis used to charge collected on cost pool to the product. So that the calculation of the cost through Time Driven activity-based costing system, the company obtain more precise information and accurate.


2018 ◽  
Vol 6 (2) ◽  
pp. 124-146 ◽  
Author(s):  
Emmanuel Lubem Asenge ◽  
Hembadoon Sarah Diaka ◽  
Alexander Terna Soom

Many studies indicates that entrepreneurial mindset is a critical factor in the accumulation, evaluation and selection of the knowledge which can lead an individual into potential business opportunities thereby enhancing entrepreneurial outcomes such as firm performance. This study examined the effect of entrepreneurial mindset on the performance of small and medium scale enterprises in Benue State. The focus of the research was to measure the entrepreneurs’ mindset exhibited through innovativeness, creativity, business alertness and risk taking and how these attributes contributed to the performance of SMEs. The research focused on a population of 650 small and medium scale enterprises based in Makurdi metropolis. A questionnaire was used to collect data from a sample of 250 SMEs in Makurdi metropolis which were selected through stratified random sampling method. Collected data were analyzed using descriptive and inferential statistics with the aid of Statistical Package for Social Sciences (SPSS). Correlation and multiple regression analysis were employed to analyse the data and test the hypotheses. The study revealed that innovativeness, creativity, business alertness and risk taking were significant in affecting performance of SMEs. The study concluded that entrepreneurial mindset or lack of it has a major effect on SMEs performance and if any economy is bended towards development and growth, it would have to embrace this concept. It recommended that all the policy makers and all stake holders should re-strategize and create forums that can promote entrepreneurial mindset among the existing and potential entrepreneurs.


2021 ◽  
Vol 45 ◽  
Author(s):  
Anna Regina Tiago Carneiro ◽  
Osvaldo Toshiyuki Hamawaki ◽  
Ana Paula Oliveira Nogueira ◽  
Arthur Felipe Eustáquio e Silva ◽  
Raphael Lemes Hamawaki ◽  
...  

ABSTRACT The selection indexes aggregate information to multiple characters and, with this, they are able to carry out the selection of a set of variables simultaneously. The objective was to verify the genetic potential of agronomic traits and to select soybean F3:4 progenies based on different selection strategies. 123 progenies and the parents were sown in randomized blocks with two replications. The gains of direct selection by the indexes, the sum of “ranks” and the genotype-ideotype were lower for all characters when compared to the gains of direct and indirect selection. The rank sum index stood out for achieving the highest total gain with 37.11%. The index of the genotype-ideotype obtained a lower gain (-0.48%) for the character number of days for flowering compared to the sum index of “ranks” (-0.54%) and reached a negative gain for the attribute insertion height of the first pod with -1.82%. The genetic potential of the F3:4 population is high and allows different selection strategies to be applied to reach superior genotypes. The progenies UFU 72, UFU 116, UFU 86, UFU 45, UFU 117, UFU 56, UFU 5, UFU 106, UFU 6, UFU 4, UFU 73, UFU 101, UFU 96, UFU 90, UFU 123, UFU 116, UFU 88, UFU 65, UFU 70, UFU 3, UFU 69 and UFU 37 were selected by both selection indexes. The UFU 72, UFU 90, UFU 88 and UFU 69 progenies are agronomically superior both in direct and indirect selection, as in Mulamba and Mock (1978) sum of “ranks” selections and genotype-ideotype.


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