Physiological Characterization of Parents of Sorghum Mapping Populations Exposed to Water-deficit Stress

Physiological Characterization of Parents of Sorghum Mapping Populations Exposed to Water-deficit Stress
Author: Regina Enninful
Publisher:
Total Pages:
Release: 2019
Genre:
ISBN:

Changing climate presents new challenges to agricultural production and global climate models project increased intensity and magnitude in water-deficit stress conditions in the future. This is especially challenging for the arid and semi-arid regions of the world, where sorghum forms an important component of the cropping system. The research objective was to characterize eleven genetically and geographically diverse sorghum Nested Association Mapping parental lines (Ajabsido, SC1103, SC265, P898012, SC35, Macia, SC283, SC1345, Segaolane, SC971 and RTx430 - the common parent) for shoot and root related physiological parameters during the vegetative and grain filling stages. Using a lysimeter based experiment in the greenhouse, water-deficit stress (55 % to 60 % field capacity) imposed for 15 days during the vegetative stage recorded significant variation between water-deficit stress and well-watered treatments for all physiological and agronomic traits regardless of the genotypic variance, except for rooting depth. The genotype by treatment interaction indicated stem height to be not only under genetic control but was subject to complex effects of the watering regimes. Transpiration efficiency and carbon isotope discrimination increased for water-deficit stressed plants. A significantly higher biomass partitioning to the roots was detected under water-deficit stress compared with the well-watered plants. In Ghana, another experiment focusing on the vegetative stage with two levels of water-deficit stress imposed on selected set of sorghum genotypes, recorded a greater decrease for shoot and root related traits under the more severe stress (50 % to 55 % FC; lasting for 21 days) than the moderate water-deficit condition (60 % to 65 % FC; lasting for 15 days). The mean cumulative water transpired (liters) during the 21 days period was 2.32 for the severe water-deficit stress, 6.88 for the moderate water-deficit stress, and 10.7 for the well-watered condition. In the grain filling experiments conducted in both the greenhouse and on the field, water-deficit stress induced variations in grain number and grain weight along different positions on the panicle among the tested genotypes. In this regard, differences in panicle positional grain number accounted for differences in panicle positional grain weight as the positional individual grain weight was not affected by the stress. Regardless of the watering treatments however, differences in grain numbers and grain weight among genotypes resulted from the diversity in panicle architecture other than grain filling dynamics. In both the greenhouse and field experiments, SC1103 did not record any significant difference between the watering treatment for all measured growth and yield traits. Spearman's rank correlations indicated the ability to select for water-deficit tolerance traits in the greenhouse that would partially represent rankings on the field. Generally, performance of genotypes such as SC35 portrayed a higher level of tolerance to water-deficit stress whereas other genotypes such as SC971 depicted significantly higher level of susceptibility. Findings from this research is helpful for providing pathways to map genomic regions responsible for increased resilience to water-deficit stress.

Physiological and Genetic Characterization of Sorghum Exposed to Early Season Chilling and Terminal Heat and Drought Stress

Physiological and Genetic Characterization of Sorghum Exposed to Early Season Chilling and Terminal Heat and Drought Stress
Author: Anuj Chiluwal
Publisher:
Total Pages:
Release: 2018
Genre:
ISBN:

Sorghum (Sorghum bicolor (L.) Moench) is one of the hardiest crop to abiotic stresses compared with other grain crops. However early stage chilling, terminal heat and drought stress are three most damaging abiotic stresses that have limited sorghum productivity in the US Great plains and other locations having similar environmental conditions. Three studies were conducted with an overall goal aimed at increasing grain sorghum's resilience to harsh climatic conditions. In the first study, four promising chilling stress tolerant sorghum advanced breeding lines, a known early stage chilling tolerant Chinese landrace (Shan Qui Red - SQR) and a susceptible US elite cultivar (RTx430) as checks were assessed for chilling tolerance during emergence and early growth under field and controlled environments. Aerial phenotyping using unmanned aircraft systems (UAS) fitted with multispectral camera was used to capture reflectance-based vegetation indices (NDVI and NDRE) in field experiments. Some advanced breeding lines with superior agronomic background also recorded significantly better emergence, seedling growth and vigor compared to SQR under chilling conditions. Aerial phenotyping indices from images taken between 30 and 60 days after emergence were consistently correlated with destructive measurements under early plantings, indicating their effectiveness in differentiating chilling responses. Second study was conducted to understand physiological mechanisms inducing heat stress resilience in sorghum during flowering. A diverse set of sorghum inbreds and selected hybrids were tested under greenhouse, growth chamber facilities and field conditions. A highly conserved early-morning-flowering mechanism was observed across all the inbreds and hybrids, with the peak anthesis wherein >90% of florets completed flowering within 30 min after dawn. The conserved response was consistent even under drought stress and heat stress exposure imposed at different times of the day. Our findings report a novel heat escaping early-morning-flowering mechanism effectively employed by sorghum to minimize heat stress impact at anthesis. Another experiment with sequential increase in daytime temperature treatments suggest heat stress induced loss in pollen viability to be a key factor resulting in reduced seed-set and grain yield. The findings suggest heat stress could have a greater impact on post-pollen germination processes such as fertilization, embryo formation and development. We identified a heat tolerant genotype "Macia" which appears to be a promising donor for developing improved heat tolerant sorghum hybrids. In the third study, a bi-parental recombinant inbred lines (RILs) mapping population developed from elite post flowering drought susceptible cultivar (RTx430) and a known drought tolerant cultivar (SC35) were evaluated under wide spectrum of environments and moisture conditions. Several novel and major QTL for grain yield, panicle neck diameter, effective quantum yield of photosystem II and chlorophyll content were identified. The genomic regions and the candidate genes within these regions can potentially help in improving source and sink dynamics in sorghum under diverse environments. The findings from these studies will complement ongoing efforts in developing future sorghum with enhanced resilience to different abiotic stresses that continue to limit sorghum productivity.

Sorghum

Sorghum
Author: Ignacio A. Ciampitti
Publisher: John Wiley & Sons
Total Pages: 528
Release: 2020-01-22
Genre: Technology & Engineering
ISBN: 0891186271

Sorghum is among the top five cereals and one of the key crops in global food security efforts. Sorghum is a resilient crop under high-stress environments, ensuring productivity and access to food when other crops fail. Scientists see the potential of sorghum as a main staple food in a future challenged by climate change. The contributors provide a comprehensive review of sorghum knowledge. The discussion covers genetic improvements, development of new hybrids, biotechnology, and physiological modifications. Production topics include water and nutrient management, rotations, and pest control. Final end uses, sorghum as a bioenergy crop, markets, and the future of sorghum are presented. IN PRESS! This book is being published according to the “Just Published” model, with more chapters to be published online as they are completed.

Water Stress and Crop Plants

Water Stress and Crop Plants
Author: Parvaiz Ahmad
Publisher: John Wiley & Sons
Total Pages: 784
Release: 2016-06-08
Genre: Science
ISBN: 1119054478

Plants are subjected to a variety of abiotic stresses such as drought, temperature, salinity, air pollution, heavy metals, UV radiations, etc. To survive under these harsh conditions plants are equipped with different resistance mechanisms which vary from species to species. Due to the environmental fluctuations agricultural and horticultural crops are often exposed to different environmental stresses leading to decreased yield and problems in the growth and development of the crops. Drought stress has been found to decrease the yield to an alarming rate of some important crops throughout the globe. During last few decades, lots of physiological and molecular works have been conducted under water stress in crop plants. Water Stress and Crop Plants: A Sustainable Approach presents an up-to-date in-depth coverage of drought and flooding stress in plants, including the types, causes and consequences on plant growth and development. It discusses the physiobiochemical, molecular and omic approaches, and responses of crop plants towards water stress. Topics include nutritional stress, oxidative stress, hormonal regulation, transgenic approaches, mitigation of water stress, approaches to sustainability, and modern tools and techniques to alleviate the water stress on crop yields. This practical book offers pragmatic guidance for scientists and researchers in plant biology, and agribusinesses and biotechnology companies dealing with agronomy and environment, to mitigate the negative effects of stress and improve yield under stress. The broad coverage also makes this a valuable guide enabling students to understand the physiological, biochemical, and molecular mechanisms of environmental stress in plants.

Mineral Nutrition of Plants: Principles and Perspectives

Mineral Nutrition of Plants: Principles and Perspectives
Author: Emanuel Epstein
Publisher: Sinauer
Total Pages: 536
Release: 1853
Genre: Nature
ISBN:

Nearly all the chemical elements that make up living things are mineral elements, the ultimate source of which is rock weathered into soil. In this thoroughly revised 2nd edition, Epstein and Bloom explain that plant roots 'mine' these nutrients elementsfrom their inorganic substrate and introduce them into the realm of living things.

Next-Generation Plant Breeding Approaches for Stress Resilience in Cereal Crops

Next-Generation Plant Breeding Approaches for Stress Resilience in Cereal Crops
Author: Mallana Gowdra Mallikarjuna
Publisher: Springer Nature
Total Pages: 507
Release: 2022-09-15
Genre: Technology & Engineering
ISBN: 9811914451

This edited book highlights the gravity and efficacy of next-generation breeding tools for the enhancement of stress-resilience in cereals, especially in the context of climate change, pests, diseases, and abiotic stresses. The content of the book helps in understanding the application of emerging genetic concepts and neoteric genomic approaches in cereal breeding. It collates all the latest information about enhancing the stress resilience in cereal crops for overcoming food security issues. Cereals have predominantly been used as a staple food since time immemorial and contribute more than 50% of the caloric requirement of the global population. However, in cereals, the yield losses due to various stresses are very high, considering the crop growth stage and stress sensitivity. Therefore, to feed and nourish the generations in the era of climate change, it is imperative to develop stress-resilient cereal cultivars. This book explores newly developed next-generation breeding tools, viz., genome-wide association studies, genomic prediction, genome editing, and accelerated generation advancement methodologies, which revealed promising outcomes by enhancing the stress resilience in cereals with yield potential. This book is useful for postgraduate students specializing in plant breeding, plant stress physiology, plant genomics, agriculture, and agronomy. It is of immense value to scientific community involved in teaching, research, and extension activities related to cereal cultivation.

International Crop Science I

International Crop Science I
Author: Dwayne R. Buxton
Publisher:
Total Pages: 938
Release: 1993
Genre: Technology & Engineering
ISBN:

Sustainable agriculture. Environmental change. Biodiversity. Crop improvement. Physiology and molecular biology. Regulation of transgenic plants. Working group reports. Constitution of International Crop Science Congress. Report of continuing committee.

Genetic Enhancement of Rabi Sorghum

Genetic Enhancement of Rabi Sorghum
Author: Sanjana Reddy
Publisher: Academic Press
Total Pages: 249
Release: 2015-05-28
Genre: Technology & Engineering
ISBN: 0128019395

Genetic Enhancement of Rabi Sorghum – Adapting the Indian Durras presents both the historical background and the recent research done in breeding this important world crop for more global production. Its chapters cover topics in origin and taxonomy, morphology and breeding behavior, genetics, and cytogenetics, also looking at production, nutrition, and alternate uses. The durra race is Ethiopian in origin and its introgression with wild forms permitted adaptation to drier conditions. These have migrated and adapted to the currently known crop that is cultivated in the winter season and commonly called rabi sorghums. Grown under receding soil moisture conditions, rabi sorghums have tolerance to abiotic stresses apart from biotic stresses, unlike the rainy sorghums that are grown widely in the world. However, they must be more resilient to rapid changes in climate, for example. The variability from winter sorghums is being introgressed into rainy sorghums. With the yield plateaus reached and sorghum gaining importance as a food crop, this book will be of importance to those studying durras and their breeding. - Presents both the historical background and most recent research done in breeding rabi sorghum for more global production - Provides information on the adaptation of the crop and the ways it has migrated to the currently known crop, which is cultivated in winter season and commonly called as rabi sorghum - Explores strategies for resilience as the crop must be prepared to withstand rapid and varying changes in climate

Sorghum and Millets Diseases

Sorghum and Millets Diseases
Author: John F. Leslie
Publisher: John Wiley & Sons
Total Pages: 524
Release: 2008-02-28
Genre: Technology & Engineering
ISBN: 0470384700

This work is based on the Mexico 2000 meeting under the auspices of ICRISAT (International Crops Research Institute for Semi-Arid Tropics) and INTSORMIL (International Sorghum and Millet Collaborative Research Support Program). Sorghum and millet are very important agronomic crops in many parts of the world, specifically in the semi-arid regions in warm areas. The crops are of great significance in supplying food and feed in the developing areas of Latin America, Africa, and Asia.

Drought Stress Tolerance in Plants, Vol 1

Drought Stress Tolerance in Plants, Vol 1
Author: Mohammad Anwar Hossain
Publisher: Springer
Total Pages: 538
Release: 2016-05-25
Genre: Technology & Engineering
ISBN: 3319288997

Abiotic stress adversely affects crop production worldwide, decreasing average yields for most of the crops to 50%. Among various abiotic stresses affecting agricultural production, drought stress is considered to be the main source of yield reduction around the globe. Due to an increasing world population, drought stress will lead to a serious food shortage by 2050. The situation may become worse due to predicated global climate change that may multiply the frequency and duration and severity of such abiotic stresses. Hence, there is an urgent need to improve our understanding on complex mechanisms of drought stress tolerance and to develop modern varieties that are more resilient to drought stress. Identification of the potential novel genes responsible for drought tolerance in crop plants will contribute to understanding the molecular mechanism of crop responses to drought stress. The discovery of novel genes, the analysis of their expression patterns in response to drought stress, and the determination of their potential functions in drought stress adaptation will provide the basis of effective engineering strategies to enhance crop drought stress tolerance. Although the in-depth water stress tolerance mechanisms is still unclear, it can be to some extent explained on the basis of ion homeostasis mediated by stress adaptation effectors, toxic radical scavenging, osmolyte biosynthesis, water transport, and long distance signaling response coordination. Importantly, complete elucidation of the physiological, biochemical, and molecular mechanisms for drought stress, perception, transduction, and tolerance is still a challenge to the plant biologists. The findings presented in volume 1 call attention to the physiological and biochemical modalities of drought stress that influence crop productivity, whereas volume 2 summarizes our current understanding on the molecular and genetic mechanisms of drought stress resistance in plants.