scholarly journals Major Sorghum Production Constraints and Coping Mechanisms: The Case of Anthracnose (Colletotrichum sublineolum)

Author(s):  
Kebede Dessalegn Lemu ◽  
Peter Ogbonna ◽  
Christian Agbo ◽  
Dagnachew Lule

This paper attempts to review the major sorghum production constraints, the progress and perspective on sorghum anthracnose (Colletotrichum sublineolum) resistance breeding. The importance of anthracnose in sorghum production and breeding for resistance status and progress were also primly discovered. Sorghum is an ancient environment resilient crop and believed to be a future crop due to its important merits like tolerant to stresses, wide adaptability and low input requirement. Insects and disease are major biotic impediments to realizing the yield potential of the crop. Anthracnose disease caused by Colletotrichum sublineolum is the most important disease that severely affecting the crop in all sorghum producing regions of the world. Research results revealed that anthracnose resulted in 30-50% or greater yield losses. Several management strategies such as, cultural, chemical and using resistance varieties have been developed. Employing host-plant resistance is the most economical and environmentally friendly approach which can successfully control the disease. Breeding assisted with molecular markers plays a great role in resistance breeding programme as it makes easy to screen large number of genotypes at once. Recent advancement of molecular breeding and bio-informatics tools are playing a significant role in efficiencies and precisions of resistance breeding. QTLs or genomic area for resistance were identified using traditional molecular markers and recent research results revealed discoveries of specific gene and locus using high throughput markers like SNPs using GWAS approach. The discovery of genes/QTL associated with the resistance trait, using the high through put molecular markers like SNPs, facilitates the easiest way for gene pyramiding from different individual genotypes to a single variety, introgression into adapted elite cultivar through marker assisted and editing genes for elite landraces to develop durable resistance varieties. Transgenic approach is now a day becoming a powerful tool to utilize novel alien genes for crop improvement including anthracnose resistance breeding in sorghum.

2002 ◽  
pp. 615-618 ◽  
Author(s):  
E. Lerceteau-Köhler ◽  
P. Roudeillac ◽  
M. Markocic ◽  
G. Guérin ◽  
K. Praud ◽  
...  

There is a strong interaction between irrigation and crop improvement, irrigation creating new opportunities and challenges for plant breeders while depending on their progress for its full benefits to be realized. In temperate environments the primary emphasis is on raising yield potential, especially as irrigation enhances the use of agrichemical inputs. Efficiency of water and energy use through the modification of physiological processes and of sensitivity to stress at various stages of the life cycle is also sought. In tropical environments, breeding for greater yield potential and more comprehensive pest and disease resistance are still important. However, shortening the length of the life cycle, reducing its sensitivity to seasonal signals and increasing yield per day may be more important than raising yield per crop because of the scope for multiple cropping made possible by irrigation in the tropics in the absence of contraints by low temperatures.


2019 ◽  
pp. 187-193
Author(s):  
Pandiyan M ◽  
Senthil N ◽  
Krishnaveni A ◽  
Sivakumar C ◽  
Singh BB ◽  
...  

The Blackgram culture VBG04-008 is a cross derivative of blackgram Vamban 3 x Vigna mungo var. silvestris 8 is released as TNAU blackgram VBN (Bg) 7 maturing in 65-70 days with an average height of 17 cm and suited for cultivation under both under rainfed and irrigated conditions. It has a yield potential of 981 Kg per hectare. This culture is resistant to Yellow Mosaic Virus, Powdery mildew and Leaf Curl Virus and less damage of pod borer. It possesses desirable characters like high protein content (21.05%), crude fibre (5.90g/100g) and iron (3.76 mg/100g). Grains are medium sized with black in colour. It is recommended for cultivation in Tamil Nadu, Andhra Pradesh, Karnataka and Orissa. Keywords: VBG04-008; Blackgram; VBN 7 Mung Bean Yellow Mosaic Virus; Powdery mildew-Rainfed; Irrigated


2020 ◽  
Vol 61 (1) ◽  
pp. 25-36
Author(s):  
Clayton G. Campbell ◽  
Mio Nagano

Buckwheat crop improvement by breeding has been taking place over the past 100 years or more. During this time there has been improvements in many desirable agronomic characteristics which has resulted in higher yields in many of the breeding programs. Phenotypic modifications, such as dwarf, semi-dwarf and branching have been reported. There has also been an effort to increase flower number as this has been shown in cross pollinating buckwheat, to increase yields. Flower cluster modifications and their effects on yield have also been studied. Increased reports on the discovery of buckwheat wild species have been reported from several programs with many interspecific crosses having taken place. Several of these crosses were performed with Fagopyrum esculentum in efforts to increase variability which can be used to increase yield potential as well as to obtain increased nutritional components.  More recent efforts have focused on the development of self-pollinating buckwheat, both from introgression of genes from Fagopyrum homotropicum as well as from mutations in cross pollinating buckwheat. The main problem has been in breeding depression which has occurred in many of the reported attempts. However, high yielding homomorphic, self-pollinating varieties have been developed and are now in commercial production. There is now emphasis being placed on many of the nutritional aspects of buckwheat flour as well as value added components. It is expected that this will increase over time.  Key words: Buckwheat breeding, homomorphic, autogamous buckwheat.   Izvleček Žlahtnjenje ajde poteka že več kot 100 let. V tem času je bila dosežena izboljšava željenih agronomskih lastnosti, kar je pri mnogih programih žlahtnjenja omogočilo večje pridelke. Raziskovalci poročajo o fenotipskih modifikacijah, kot je pritlikava ali pol-pritlikava rast in razvejanje. Za povečanje pridelka so bile raziskane modifikacije socvetij. Število poročil o odkritjih divjih sorodnikov ajde in o mnogih medvrstnih križanjih se je v zadnjem času povečalo. V mnoga od teh križanj je bila vključena navadna ajda (Fagopyrum esculentum), da bi povečali  variabilnost, kar bi lahko omogočilo povečanje pridelka in izboljšanje prehranskih lastnosti. Novejša prizadevanja so se osredotočila na razvoj samooplodnosti pri ajdi, z vključitvijo genov vrste Fagopyrum homotropicum, kot tudi mutacij pri ajdi, ki se je opraševala navzkrižno.  Pri tem je bila glavna težava preseči  depresijo zaradi samooploditev, depresija se je pojavila pri večih poskusih samooploditve. Ne glede na to je uspelo dobiti visokorodne homomorfne samooplodne sorte za ponudbo na trgu semen. Sedaj se prizadevanja usmerjajo k izboljšanju prehranske vrednosti ajde in pomembnih sestavin v ajdovi moki. Pričakovati je, da se bo pomen prehranske vrednosti ajde sčasoma še povečeval. Ključne besede: žlahtnjenje ajde, homomorfnost, samo­oplodna ajda


2021 ◽  
Vol 17 (1) ◽  
pp. 45
Author(s):  
Tasliah Tasliah

Rice is the staple food for more than half of the world's population. Rice production in 2050 must increase by at least 50% to keep up with the population growth. Efforts to increase rice production continue using various strategies. Breeders apply multiple approaches including application of molecular markers in developing varieties better than the previous ones. Since the discovery of the restriction fragment length polymorphism (RFLP) markers in 1980s and the development of polymerase chain reaction (PCR) method, many types of molecular markers have been developed and applied to various crops including rice. Various molecular approaches to map genetic loci associated with rice superior traits were conducted. The mapped loci are very useful for rice breeding purposes. This paper reports the results of mapping and breeding economically important traits in rice, mainly those related to abiotic stresses, agronomic traits, yield, and yield quality. These included characters of semidwarf stature, aromatic grain, high yield potential, eating quality, higher Zn and Fe grain, more tolerant to abiotic stresses, such as salinity, drought, phosphate deficiency, Al toxicity and Fe toxicity, submergence, as well as early maturity character. The mapped characters can be transferred using marker-assisted backcrossing (MABC) method into cultivated rice genotypes well-adopted by farmers. Several countries including Indonesia have benefited from this breeding method, and Indonesia have released several rice varieties developed through MABC. These include rice varieties such as Code, Angke, Inpari 30, Inpari Blas, Inpari HDB, Bio Patenggang Agritan, and Bioni 63 Ciherang Agritan


Author(s):  
J. W. Forster ◽  
E. S. Jones ◽  
R. Kölliker ◽  
M. C. Drayton ◽  
J. L. Dumsday ◽  
...  

2021 ◽  
pp. 567-586
Author(s):  
Jerome D. Franckowiak ◽  
◽  
Gregory J. Platz ◽  

This chapter focuses on breeding barley for durable resistance to net and spot forms of net blotch. It starts by reviewing how Pyrenophora teres f. teres can cause net form net blotch. The chapter then goes on to examine the molecular markers that can be identified to provide resistances to net form net blotch. A section on the population dynamics of barley–P. teres f. teres interactions is also provided. The chapter also reviews how breeding crops with specific genes can help to create durable resistance to net form blotch. It moves on to discuss how Pyrenophora teres Drechs. f. maculata can cause spot form net blotch and how identifying specific molecular markers can help provide resistance to this form of net blotch. The chapter concludes by highlighting the importance of combining durable resistance to both forms of net blotch.


Weed Science ◽  
2020 ◽  
Vol 68 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Erik W. Ohlson ◽  
Michael P. Timko

AbstractCowpea witchweed [Striga gesnerioides (Willd.) Vatke] is a primary constraint of cowpea [Vigna unguiculata (L.) Walp.] production in West Africa. Previously, seven S. gesnerioides races were classified based upon host specificity and genotypic profiling. Because race number and distribution are dynamic systems influenced by gene flow, genetic drift, and natural selection, a thorough investigation of S. gesnerioides diversity and the effectiveness of known sources of resistance in cowpea is needed to develop varieties with durable and broad-spectrum Striga resistance. In this study, we screened seven cowpea lines against 58 unique S. gesnerioides populations collected from across nine West African countries. Individuals from 10 S. gesnerioides populations were genotyped with simple sequence repeat (SSR) markers. We identified six races of S. gesnerioides based on their parasitism of the seven cowpea lines with known differential resistance genotypes. No cowpea line was resistant to all 58 Striga populations and none of the Striga populations were able to overcome the resistance of all seven lines. A novel race, SG6, of the parasite collected from Kudu, Nigeria, was found to overcome more cowpea resistance genes than any previously reported race. SSR analysis indicates that Striga populations are highly differentiated and genetic relatedness generally corresponds with geographic proximity rather than their host compatibility. Due to the dearth of broad-spectrum resistance found among Striga-resistant cowpea lines, there exists a need to stack multiple Striga resistance genes in order to confer broad-spectrum and durable resistance.


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