scholarly journals Breeding Maize Maternal Haploid Inducers

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 614
Author(s):  
Henrique Uliana Trentin ◽  
Ursula K. Frei ◽  
Thomas Lübberstedt

Maize doubled haploid (DH) lines are usually created in vivo, through crosses with maternal haploid inducers. These inducers have the inherent ability of generating seeds with haploid embryos when used to pollinate other genotypes. The resulting haploid plants are treated with a doubling agent and self-pollinated, producing completely homozygous seeds. This rapid method of inbred line production reduces the length of breeding cycles and, consequently, increases genetic gain. Such advantages explain the wide adoption of this technique by large, well-established maize breeding programs. However, a slower rate of adoption was observed in medium to small-scale breeding programs. The high price and/or lack of environmental adaptation of inducers available for licensing, or the poor performance of those free of cost, might explain why smaller operations did not take full advantage of this technique. The lack of adapted inducers is especially felt in tropical countries, where inducer breeding efforts are more recent. Therefore, defining optimal breeding approaches for inducer development could benefit many breeding programs which are in the process of adopting the DH technique. In this manuscript, we review traits important to maize maternal haploid inducers, explain their genetic basis, listing known genes and quantitative trait loci (QTL), and discuss different breeding approaches for inducer development. The performance of haploid inducers has an important impact on the cost of DH line production.

2019 ◽  
Vol 132 (12) ◽  
pp. 3227-3243 ◽  
Author(s):  
Vijay Chaikam ◽  
Willem Molenaar ◽  
Albrecht E. Melchinger ◽  
Prasanna M. Boddupalli

Key Message Increased efficiencies achieved in different steps of DH line production offer greater benefits to maize breeding programs. Abstract Doubled haploid (DH) technology has become an integral part of many commercial maize breeding programs as DH lines offer several economic, logistic and genetic benefits over conventional inbred lines. Further, new advances in DH technology continue to improve the efficiency of DH line development and fuel its increased adoption in breeding programs worldwide. The established method for maize DH production covered in this review involves in vivo induction of maternal haploids by a male haploid inducer genotype, identification of haploids from diploids at the seed or seedling stage, chromosome doubling of haploid (D0) seedlings and finally, selfing of fertile D0 plants. Development of haploid inducers with high haploid induction rates and adaptation to different target environments have facilitated increased adoption of DH technology in the tropics. New marker systems for haploid identification, such as the red root marker and high oil marker, are being increasingly integrated into new haploid inducers and have the potential to make DH technology accessible in germplasm such as some Flint, landrace, or tropical material, where the standard R1-nj marker is inhibited. Automation holds great promise to further reduce the cost and time in haploid identification. Increasing success rates in chromosome doubling protocols and/or reducing environmental and human toxicity of chromosome doubling protocols, including research on genetic improvement in spontaneous chromosome doubling, have the potential to greatly reduce the production costs per DH line.


2020 ◽  
Vol 80 (03) ◽  
Author(s):  
R. K Khulbe ◽  
A. Pattanayak ◽  
Lakshmi Kant ◽  
G. S. Bisht ◽  
M. C. Pant ◽  
...  

The use of in vivo haploid induction system makes the doubled haploid (DH) technology easier to adopt for the conventional maize breeders. However, despite having played an important role in the initial developmental phases of DH technology, Indian maize research has yet to harvest its benefits. Haploid Inducer Lines (HILs) developed by CIMMYT are being widely used in maize breeding programmes in many countries including India. There, however, is no published information on the efficiency of DH line production using CIMMYT HILs in Indian maize breeding programmes. In the present study, the efficiency of DH production using CIMMYT’s tropically adapted inducer line TAILP1 was investigated with eight source populations including two of sweet corn. The average haploid induction rate (HIR) of TAILP1 was 5.48% with a range of 2.01 to 10.03%. Efficiency of DH production ranged from 0.14 to 1.87% for different source populations with an average of 1.07%. The information generated will be useful for maize breeders intending to use DH technology for accelerated development of completely homozygous lines.


Euphytica ◽  
2012 ◽  
Vol 185 (3) ◽  
pp. 481-490 ◽  
Author(s):  
Vanessa Prigge ◽  
Wolfgang Schipprack ◽  
George Mahuku ◽  
Gary N. Atlin ◽  
Albrecht E. Melchinger

Wind is an endless resource which is abundantly found in nature. Harnessing wind energy for producing electricity is one of the ways for buildings for a sustainable future. Small-scale wind turbines could be a reliable energy source for usage in homes and in autonomous applications in locations that are far away from the grid power. Small wind turbines operating at low wind speeds regularly face the problem of poor performance due to small rotor size. To increase the power production additional wind turbines are installed. This increases the overall cost of the project. To reduce the cost and to improve the efficiency, multiple rotors are connected through a single shaft to the fixed single generator. The Implementation of this design permits start up at lower wind speeds, increasing the start-up torque and thus improving the overall performance of the turbine. This paper elaborates the design and fabrication of such a wind turbine. [1] [2] [3]


Genetika ◽  
2021 ◽  
Vol 53 (1) ◽  
pp. 51-64
Author(s):  
Rahime Cengiz ◽  
Mesut Esmeray

In vivo doubled haploid technique has been widely used in advanced maize breeding programs due to cost, labor and time advantages and increase in efficiency. However, the number of available inducer lines in the world is sufficient. Six BC1 breeding populations including RWS and RWK-76 haploid inducer lines and late temperate ADK-451, ADK-737 and ADK-455 lines were developed by Sakarya Maize Research Institute (MRI) in Turkey. The RWS and RWK-76 haploid inducer lines were used as donors. Pedigree method was employed to develop the inducer lines. Anthocyanin coloration of plant, tassel length, branch number of tassel, plant height, days to flowering, embryo-endosperm colorfulness and haploid induction rate (HIR) were determined. The genotypes with the best characteristics were selected. The families from BC1F3 to BC1F7 were hybridized to liguleless line to determine the HIR and families with HIR over 8% were selected from BC1 populations. The HIR, plant height and days to tassel flowering values of in-1021 and in-1076 candidate haploid inducer lines were 10.5 and 12.3%, 195 and 200 cm, and 69 and 68 days, respectively. The HIR value of RWS donor haploid inducer ranged from 8.9 to 11.3% and for RWK-76 from 7.3 to 9.8%. Simple Sequence Repeats (SSRs) markers were used to identify genetic similarity between late temperate haploid inducer lines and donors. The similarity rates of in-1021 and in-1076 inducer lines to the RWS donor were 38 and 15%, and to the RWK-76 donor were 23 and 27%. The similarity rate between the two candidate inducer lines was 30%. The results indicated that the late temperate haploid inducer lines developed will increase the efficiency of maize breeding.


2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.


Author(s):  
I. F. Gorlov ◽  
A. A. Mosolov ◽  
G. V. Komlatskiy ◽  
M. A. Nesterenko ◽  
K. D. Nimbona ◽  
...  

The article presents materials on the study of the possibility of reproduction and increase in the herd of highly productive cows through the use of embryo transplantation technology. The classical (in vivo) and more modern, developing (in vitro) methods of embryotransfer, their positive and negative sides are considered in detail. The possibility of accelerating the breeding process by using the method of transplantation, in which from one cow can be obtained from 10 to 100 calves, which will allow for 4-5 years, almost any herd (of any size and breed) with the help of biotechnology to turn into a cattle-breeding enterprise of the most modern level. At the same time, heifers obtained from unproductive cows can be used as "surrogate" mothers who are transplanted with the best donor embryos, which allows to obtain a full-fledged offspring adapted to local environmental conditions. A detailed scheme of obtaining, evaluation, storage, as well as the cost and economic effect of embryo transplantation was calculated, the market was evaluated, the required annual volume of transplants and the number of donor cows for large livestock farms were determined. As a positive example of "Scientific-production enterprise "Centre of biotechnology and embryo transfer" in 2014, implemented a project for accelerated replacement and genetic improvement of the dairy herd, engraftment averaged 57-69%, and the economic effect of the enterprise from getting a single animal by the method of embryo transfer, compared with imports of similar close in quality, ranged from 60 to 100 thousand rubles on his head. It is shown that it is necessary to organize at the state level a developed service for embryo transplantation to reduce the cost of embryo transfer and the possibility of creating in a short time in the country's own highly productive breeding nucleus of dairy and beef cattle, which will reduce, and in the future completely eliminate, import dependence on cattle products.


Author(s):  
Сергей Борисович Казаков ◽  
Дмитрий Михайлович Шишов ◽  
Антон Игоревич Ларин ◽  
Александр Петрович Николаев ◽  
Аза Валерьевна Писарева

В статье представлен обзор существующих технических решений в сфере мониторинга и предотвращения апноэ во сне. Произведён анализ существующих аппаратов для предотвращения апноэ, который показал, что на рынке присутствует большое количество импортных моделей, однако они имеют довольно высокую цену. Разработанный нами Российский аналог проектируемого аппарата, при схожих характеристиках, будет иметь более привлекательную цену, чем у импортных приборов. Интегрирование датчика влажности в персональную маску пациента даёт возможность отслеживать остановки дыхания пациента во время сна, и тем самым включать процесс принудительной подачи дыхательной смеси именно в тот момент, когда она необходима для устранения патологии. Целью научной работы является разработка конструкции прибора и создание алгоритма программы для управления аппарата искусственной вентиляции лёгких для предотвращения апноэ во сне. Показана разработка структуры устройства аппарата. Подобран компрессор и датчик влажности с обоснованными характеристиками для создания аппарата, а также основные элементы. Разработана конструкция корпуса аппарата и разработана компоновка. Выполнено технико-экономическое обоснование разработки аппаратно-программного комплекса для предотвращения апноэ во сне. Показано, что себестоимость готового изделия достаточно конкурентна The article presents an overview of existing technical solutions in the field of monitoring and prevention of sleep apnea. An analysis of existing devices for preventing apnea was made, which showed that there are a large number of imported models on the market, but they have a fairly high price. The Russian analog of the designed device developed by us, with similar characteristics, will have a more attractive price than that of imported devices. The integration of the humidity sensor into the patient's personal mask makes it possible to monitor the patient's breathing stops during sleep, and thus enable the process of forced delivery of the respiratory mixture at the exact moment when it is necessary to eliminate the pathology. The purpose of the research is to develop the device design and create a program algorithm for controlling the artificial lung ventilation device to prevent sleep apnea. The development of the device structure is shown. The compressor and humidity sensor with reasonable characteristics for creating the device, as well as the main elements are selected. The design of the device body and its layout were developed. A feasibility study for the development of a hardware and software system for preventing sleep apnea has been completed. It is shown that the cost of the finished product is quite competitive


2020 ◽  
Vol 3 (1) ◽  
pp. 61
Author(s):  
Kazuhiro Aruga

In this study, two operational methodologies to extract thinned woods were investigated in the Nasunogahara area, Tochigi Prefecture, Japan. Methodology one included manual extraction and light truck transportation. Methodology two included mini-forwarder forwarding and four-ton truck transportation. Furthermore, a newly introduced chipper was investigated. As a result, costs of manual extractions within 10 m and 20 m were JPY942/m3 and JPY1040/m3, respectively. On the other hand, the forwarding cost of the mini-forwarder was JPY499/m3, which was significantly lower than the cost of manual extractions. Transportation costs with light trucks and four-ton trucks were JPY7224/m3 and JPY1298/m3, respectively, with 28 km transportation distances. Chipping operation costs were JPY1036/m3 and JPY1160/m3 with three and two persons, respectively. Finally, the total costs of methodologies one and two from extraction within 20 m to chipping were estimated as JPY9300/m3 and JPY2833/m3, respectively, with 28 km transportation distances and three-person chipping operations (EUR1 = JPY126, as of 12 August 2020).


Author(s):  
Mohammad Istiak Hossain ◽  
Jan I. Markendahl

AbstractSmall-scale commercial rollouts of Cellular-IoT (C-IoT) networks have started globally since last year. However, among the plethora of low power wide area network (LPWAN) technologies, the cost-effectiveness of C-IoT is not certain for IoT service providers, small and greenfield operators. Today, there is no known public framework for the feasibility analysis of IoT communication technologies. Hence, this paper first presents a generic framework to assess the cost structure of cellular and non-cellular LPWAN technologies. Then, we applied the framework in eight deployment scenarios to analyze the prospect of LPWAN technologies like Sigfox, LoRaWAN, NB-IoT, LTE-M, and EC-GSM. We consider the inter-technology interference impact on LoRaWAN and Sigfox scalability. Our results validate that a large rollout with a single technology is not cost-efficient. Also, our analysis suggests the rollout possibility of an IoT communication Technology may not be linear to cost-efficiency.


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