Molecular breeding for improving aluminium resistance in wheat.

Author(s):  
Jorge Fernando Pereira

Abstract This chapter aims at describing the main physiological mechanisms associated with aluminium (Al) resistance in wheat and how the research about these mechanisms has evolved to its current status. Practical aspects of phenotyping and using the molecular basis to increase Al resistance, which can be easily introduced in breeding programmes, are detailed. This chapter discusses the reliability of methods to screen root growth under Al stress, the allelic variation of genes associated with the main Al resistance mechanism in wheat, the quantitative trait loci and genomic regions that might contain minor Al tolerance genes, the use of wheat wild relatives, the uncertainties of developing transgenic wheat for greater Al resistance and the development of Al-resistant lines of durum wheat (Triticum turgidum subsp. durum).

2021 ◽  
Author(s):  
Baljeet K. Gill ◽  
Daryl L. Klindworth ◽  
Matthew N. Rouse ◽  
Jinglun Zhang ◽  
Qijun Zhang ◽  
...  

2020 ◽  
Author(s):  
Diptibala Rout ◽  
Debarchana Jena ◽  
Vineeta Singh ◽  
Manish Kumar ◽  
Pandurang Arsode ◽  
...  

Heterosis is a solitary means of exploiting hybrid vigor in crop plants. Given its yield advantage and economic importance, several hybrids in rice have been commercialized in more than 40 countries, which has created a huge seed industry worldwide. India has made commendable progress and commercialized 117 three-line indica hybrids for different ecology and duration (115–150 days), which accounted for 6.8% of total rice area in the country. Besides, several indigenous CMS lines developed in diversified genetic and cytoplasmic backgrounds are being utilized in hybrid rice breeding. NRRI, which has been pioneering to start with the technology, has developed three popular rice hybrids, viz., Ajay, Rajalaxmi, and CR Dhan 701 for irrigated-shallow lowland ecosystem. Biotechnological intervention has supplemented immensely in excavating desirable genomic regions and their deployment for further genetic enhancement and sustainability in rice hybrids. Besides, hybrid seed production creates additional job opportunity (100–105 more-man days) and comparatively more net income (70% more than production cost) than HYVs. Hence, this technology has great scope for further enhancement in per se rice productivity and livelihood of the nation.


2021 ◽  
Vol 28 ◽  
Author(s):  
Vinutha Kanuganahalli Somegowda ◽  
Laavanya Rayaprolu ◽  
Abhishek Rathore ◽  
Santosh Pandurang Deshpande ◽  
Rajeev Gupta

: The main focus of this review is to discuss the current status of the use of GWAS for fodder quality and biofuel owing to its similarity of traits. Sorghum is a potential multipurpose crop, popularly cultivated for various uses as food, feed fodder, and biomass for ethanol. Production of a huge quantity of biomass and genetic variation for complex sugars are the main motivation not only to use sorghum as fodder for livestock nutritionists but also a potential candidate for biofuel generation. Few studies have been reported on the knowledge transfer that can be used from the development of biofuel technologies to complement improved fodder quality and vice versa. With recent advances in genotyping technologies, GWAS became one of the primary tools used to identify the genes/genomic regions associated with the phenotype. These modern tools and technologies accelerate the genomic assisted breeding process to enhance the rate of genetic gains. Hence, this mini-review focuses on GWAS studies on genetic architecture and dissection of traits underpinning fodder quality and biofuel traits and their limited comparison with other related model crop species.


2011 ◽  
Vol 9 (3) ◽  
pp. 439-444 ◽  
Author(s):  
C. Rodríguez-Suárez ◽  
M. C. Ramírez ◽  
A. Martín ◽  
S. G. Atienza

Triticum urartu, the A-genome donor of tetraploid and hexaploid wheats, is a potential source of novel alleles for crop improvement. A fertile amphiploid between T. urartu (2n = 2x = 14; AuAu) and durum wheat cv ‘Yavaros’ (Triticum turgidum ssp. durum; 2n = 4x = 28, AABB) was obtained as a first step to making the genetic variability of the wild ancestor available to durum wheat breeding. The amphiploid was backcrossed with ‘Yavaros’ and the offspring from this cross was selfed. A plant from this progeny (founder line) with 28 chromosomes and active x and y subunits of the Glu-A1 locus of T. urartu was selfed, which resulted in the obtaining of 98 pre-introgression lines (pre-ILs). In this work, a set of 78 wheat chromosome-specific microsatellite markers (simple sequence repeats, SSR), uniformly distributed over the A genome, was used for marker-assisted selection of T. urartu in a durum wheat background. A total of 57 SSRs allowed a clear discrimination between T. urartu and ‘Yavaros’. This set of markers was further used for characterizing the pre-ILs, identifying and defining the T. urartu introgressed regions. The applicability of these markers is discussed.


Author(s):  
C.F. Mercer ◽  
R.N. Watson ◽  
D.R. Woodfield

Breeding for improved resistance and tolerance to the clover root-knot nematode, Meloidogyne trifoliophila, and the clover cyst nematode, Heterodera trifolii , has been successful in white c lover, Trifolium repens. White clover lines developed from three independent breeding programmes were established in field trials at Lincoln, Palmerston North, Cambridge and Kerikeri. Plants were established in areas either untreated or treated with nematicide, so as to have contrasting pest loads on the plant material and evaluated for up to 4 years. Plant vigour was scored before each grazing at each site. Clover cyst nematode cysts were counted twice in Palmerston North and all nematodes were counted in stained roots on four occasions in Cambridge. Resistant lines from the clover cyst nematode programme performed better than susceptible lines and as well as most cultivars reflecting the high level of resistance developed in this glasshouse-based programme. This resistance was also reflected in the generally lower number of cysts counted under resistant lines from Palmerston North. The root-knot nematode resistant material performed better than the susceptible and as well as most cultivars. The tolerance selections, developed under field conditions, performed as well as, or better than the cultivars. The selections from the breeding programmes have exhibited strong agronomic potential across locations and years and the best material has been crossed, with progeny being assessed in current field trials. Keywords: Heterodera trifolii, Meloidogyne trifoliophila, nematode, pasture, resistance, tolerance, white clover


2021 ◽  
Vol 12 ◽  
Author(s):  
Kelechi Uchendu ◽  
Damian Ndubuisi Njoku ◽  
Agre Paterne ◽  
Ismail Yusuf Rabbi ◽  
Daniel Dzidzienyo ◽  
...  

Cassava breeders have made significant progress in developing new genotypes with improved agronomic characteristics such as improved root yield and resistance against biotic and abiotic stresses. However, these new and improved cassava (Manihot esculenta Crantz) varieties in cultivation in Nigeria have undergone little or no improvement in their culinary qualities; hence, there is a paucity of genetic information regarding the texture of boiled cassava, particularly with respect to its mealiness, the principal sensory quality attribute of boiled cassava roots. The current study aimed at identifying genomic regions and polymorphisms associated with natural variation for root mealiness and other texture-related attributes of boiled cassava roots, which includes fibre, adhesiveness (ADH), taste, aroma, colour, and firmness. We performed a genome-wide association (GWAS) analysis using phenotypic data from a panel of 142 accessions obtained from the National Root Crops Research Institute (NRCRI), Umudike, Nigeria, and a set of 59,792 high-quality single nucleotide polymorphisms (SNPs) distributed across the cassava genome. Through genome-wide association mapping, we identified 80 SNPs that were significantly associated with root mealiness, fibre, adhesiveness, taste, aroma, colour and firmness on chromosomes 1, 4, 5, 6, 10, 13, 17 and 18. We also identified relevant candidate genes that are co-located with peak SNPs linked to these traits in M. esculenta. A survey of the cassava reference genome v6.1 positioned the SNPs on chromosome 13 in the vicinity of Manes.13G026900, a gene recognized as being responsible for cell adhesion and for the mealiness or crispness of vegetables and fruits, and also known to play an important role in cooked potato texture. This study provides the first insights into understanding the underlying genetic basis of boiled cassava root texture. After validation, the markers and candidate genes identified in this novel work could provide important genomic resources for use in marker-assisted selection (MAS) and genomic selection (GS) to accelerate genetic improvement of root mealiness and other culinary qualities in cassava breeding programmes in West Africa, especially in Nigeria, where the consumption of boiled and pounded cassava is low.


Author(s):  
Claudia Teixeira Guimaraes ◽  
Jurandir Vieira de Magalhaes

Abstract Citrate transporters belonging to the multidrug and toxic compound extrusion (MATE) family of membrane transporters in sorghum and maize, SbMATE and ZmMATE1, respectively, play a major role in aluminium (Al) tolerance. However, these MATE members show regulatory differences, as well as peculiarities in their genetic effect and mode of action. These aspects, which are discussed in this chapter, have to be considered to design successful breeding programmes in order to achieve maximum Al tolerance and, consequently, to improve grain and biomass production in regions of the world with Al toxicity. As shown in this chapter, target genes with major effects and molecular tools are available for marker-assisted breeding for improving Al tolerance both in sorghum and maize. However, wide adaptation to acid soils should be sought by pyramiding genes controlling different traits such as drought tolerance, P acquisition, resistance to diseases and other stresses commonly found in each agroecological environment.


Author(s):  
Mikel Arrieta ◽  
Glenda Willems ◽  
Jérôme DePessemier ◽  
Isabelle Colas ◽  
Alexandra Burkholz ◽  
...  

Abstract Meiotic recombination plays a crucial role in plant breeding through the creation of new allelic combinations. Therefore, lack of recombination in some genomic regions constitutes a constraint for breeding programmes. In sugar beet, one of the major crops in Europe, recombination occurs mainly in the distal portions of the chromosomes, and so the development of simple approaches to change this pattern is of considerable interest for future breeding and genetics. In the present study, the effect of heat stress on recombination in sugar beet was studied by treating F1 plants at 28 °C/25 °C (day/night) and genotyping the progeny. F1 plants were reciprocally backcrossed allowing the study of male and female meiosis separately. Genotypic data indicated an overall increase in crossover frequency of approximately one extra crossover per meiosis, with an associated increase in pericentromeric recombination under heat treatment. Our data indicate that the changes were mainly induced by alterations in female meiosis only, showing that heterochiasmy in sugar beet is reduced under heat stress. Overall, despite the associated decrease in fertility, these data support the potential use of heat stress to foster recombination in sugar beet breeding programmes.


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