Breeding for drought and nitrogen stress tolerance in maize: From theory to practice

Breeding for drought and nitrogen stress tolerance in maize: From theory to practice
Author: M. Bänzinger
Publisher: CIMMYT
Total Pages: 69
Release: 2000
Genre:
ISBN: 9706480463

Introduction - why breed for drought and low N tolerance?; Conceptual framework - breeding; Conventional approaches to improving the drought and low N tolerance of maize; Conventional approaches challenged; The challenge of breeding for drought and low N tolerance; Maize under drought and low N stress; Conceptual framework - physiology; Water and the maize plant; Nitrogen and the maize plant; Maize under drought and low N stress - consequences for breeding; Stress management; Drought; Low N stress; Statistical designs and layout of experiments; Increasing the number of replicates; Improved statistical designs; Field layout; Border effects from alleys; Secondary traits; Why use secondary traits?; How do we decide on the value of secondary traits in a drought or low N breeding program?; Secondary traits that help to identify drought tolerance; Secondary traits that help to identify low N tolerance: Selection indices - Combining information on secondary traits with grain yield; Combining information from various experiments; Breeding strategies; Choice of germplasm; Breeding schemes; Biotechnology: potential and constraints for improving drought and low N tolerance; The role of the farmer in selection; What is farmer participatory research and why is it important?; What is new about farmer participatory research?; Participatory methodologies.

Drought Stress in Maize (Zea mays L.)

Drought Stress in Maize (Zea mays L.)
Author: Muhammad Aslam
Publisher: Springer
Total Pages: 79
Release: 2015-11-20
Genre: Science
ISBN: 3319254421

This book focuses on early germination, one of maize germplasm most important strategies for adapting to drought-induced stress. Some genotypes have the ability to adapt by either reducing water losses or by increasing water uptake. Drought tolerance is also an adaptive strategy that enables crop plants to maintain their normal physiological processes and deliver higher economical yield despite drought stress. Several processes are involved in conferring drought tolerance in maize: the accumulation of osmolytes or antioxidants, plant growth regulators, stress proteins and water channel proteins, transcription factors and signal transduction pathways. Drought is one of the most detrimental forms of abiotic stress around the world and seriously limits the productivity of agricultural crops. Maize, one of the leading cereal crops in the world, is sensitive to drought stress. Maize harvests are affected by drought stress at different growth stages in different regions. Numerous events in the life of maize crops can be affected by drought stress: germination potential, seedling growth, seedling stand establishment, overall growth and development, pollen and silk development, anthesis silking interval, pollination, and embryo, endosperm and kernel development. Though every maize genotype has the ability to avoid or withstand drought stress, there is a concrete need to improve the level of adaptability to drought stress to address the global issue of food security. The most common biological strategies for improving drought stress resistance include screening available maize germplasm for drought tolerance, conventional breeding strategies, and marker-assisted and genomic-assisted breeding and development of transgenic maize. As a comprehensive understanding of the effects of drought stress, adaptive strategies and potential breeding tools is the prerequisite for any sound breeding plan, this brief addresses these aspects.

Genomic Designing of Climate-Smart Cereal Crops

Genomic Designing of Climate-Smart Cereal Crops
Author: Chittaranjan Kole
Publisher: Springer Nature
Total Pages: 321
Release: 2020-02-28
Genre: Science
ISBN: 3319933817

This book highlights modern methods and strategies to improve cereal crops in the era of climate change, presenting the latest advances in plant molecular mapping and genome sequencing. Spectacular achievements in the fields of molecular breeding, transgenics and genomics in the last three decades have facilitated revolutionary changes in cereal- crop-improvement strategies and techniques. Since the genome sequencing of rice in 2002, the genomes of over eight cereal crops have been sequenced and more are to follow. This has made it possible to decipher the exact nucleotide sequence and chromosomal positions of agroeconomic genes. Most importantly, comparative genomics and genotyping-by-sequencing have opened up new vistas for exploring available biodiversity, particularly of wild crop relatives, for identifying useful donor genes.

Breeding Studied on Drought Tolerance in Maize

Breeding Studied on Drought Tolerance in Maize
Author: Maamoun Adel-Moneam
Publisher: LAP Lambert Academic Publishing
Total Pages: 144
Release: 2010-05
Genre:
ISBN: 9783838367071

The objectives of this investigation were to test the genotypic differences in drought tolerance, estimate the heritability, and to evaluate the role of gca and sca of inbreds in hybrid under water stress. The main results were:1-Hybrids G507AxG278, L81BxG278 and G507AxL 81B were high tolerance to drought.2-Correlation between grain yield and yield components were higher under stress than non-drought in most cases. 3-All studied yield and yield components showed high broad- sense heritability estimates under stress and non-stress treatments in both seasons.4- The expected gain from direct selection for grain yield under stressed or non-stressed environments would improve the trait under consideration in a way better than the indirect selection for any other traits. 5-Inbreds L 81B, G 278 and G 507A showed positive and significant GCA effects for grain and ear yield and most of yield components traits under stress or non-stress treatments

Breeding and Selection for Drought Resistance in Tropical Maize

Breeding and Selection for Drought Resistance in Tropical Maize
Author: K. S. Fischer
Publisher:
Total Pages: 16
Release: 1983
Genre: Corn
ISBN:

Throughout the lowland wet tropics, periodic nonprotracted drought caused by irregular rainfall distribution is responsible for sizable reductions in maize yield. This is particularly true when reduced water availability coincides with the critical stage of crop development--flowoering. Such a drought cannot be escaped by genotype maturity or planting date, nor are other species necessarily better adapted. Improving resistance of maize to this particular type of drought, then, could enhance productivity and minimize farmer risk. From a comparison of sorghum and maize under drought, it appears that sorghum maintains photosynthesis and growth at lower water levels and has more developmental plasticity than maize. Increasing the dray matter available for ear development around flowering may help to reduce the detrimental effects of drought occurring at this critical stage in maize. Many morphological and physiological characters have been suggested for modification so as to enchance drought resistance in maize. At CIMMYT, one lowland tropical maize population is being improved for drought resistance through a recurrent selection program. Progenies are selected using an index based on grain yield under no stress and stress, leaf elongation rate, interval between anthesis and silking, canopy temperature and leaf area loss during grain filling. Evaluation of the progress after three cycles of recurrent selection shows a significant increase in yield under severe drought conditions. Improvement is approximately 9,5% ...

Drought phenotyping in crops: From theory to practice

Drought phenotyping in crops: From theory to practice
Author: Philippe Monneveux
Publisher: Frontiers E-books
Total Pages: 238
Release: 2014-02-12
Genre:
ISBN: 2889191818

This topic is a unique attempt to simultaneously tackle theoretical and practical aspects in drought phenotyping, through both crop-specific and cross-cutting approaches. It is designed for – and will be of use to – practitioners and postgraduate students in plant science, who are grappling with the challenging task of evaluating germplasm performance under different water regimes. In Part I, different methodologies are presented for accurately characterising environmental conditions, implementing trials, and capturing and analysing the information this generates, regardless of the crop. Part II presents the state-of-art in research on adaptation to drought, and recommends specific protocols to measure different traits in major food crops (focusing on particular cereals, legumes and clonal crops). The topic is part of the CGIAR Generation Challenge Programme’s efforts to disseminate crop research information, tools and protocols, for improving characterisation of environments and phenotyping conditions. The goal is to enhance expertise in testing locations, and to stimulate the development and use of traits related to drought tolerance, as well as innovative protocols for crop characterisation and breeding.