The various crop species are major agricultural products and play an indispensable role in sustaining human life. Over a long period, breeders strove to increase crop yield and improve quality through traditional breeding strategies. Today, many breeders have achieved remarkable results using modern molecular technologies. Recently, a new gene-editing system, named the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology, has also succeeded in improving crop quality. It has become the most popular tool for crop improvement due to its versatility. It has accelerated crop breeding progress by virtue of its precision in specific gene editing. This review summarizes the current application of CRISPR/Cas9 technology in crop quality improvement. It includes the modulation in appearance, palatability, nutritional components and other preferred traits of various crops. In addition, the challenge in its future application is also discussed.

The modern cultivated wheat has passed a long evolution involving origin of wild emmer (WEM), development of cultivated emmer, formation of spelt wheat and finally establishment of modern bread wheat and durum wheat. During this evolutionary process, rapid alterations and sporadic changes in wheat genome took place, due to hybridization, polyploidization, domestication, and mutation. This has resulted in some modifications and a high level of gene loss. As a result, the modern cultivated wheat does not contain all genes of their progenitors. These lost genes are novel for modern wheat improvement. Exploring wild progenitor for genetic variation of important traits is directly beneficial for wheat breeding. WEM wheat (Triticum dicoccoides) is a great genetic resource with huge diversity for traits. Few genes and quantitative trait loci (QTL) for agronomic, quantitative, biotic and abiotic stress-related traits have already been mapped from WEM. This resource can be utilized for modern wheat improvement by integrating identified genes or QTLs through breeding.

Maize is one of the most important cereals globally and a promising cereal supplement in Bangladesh. The current study was undertaken to assess genetic diversity among nine maize genotypes. Data were recorded on seven morphological traits viz. plant height (cm), ear height (cm), ear length (cm), ear diameter (cm), number of kernels/ear, 1000-kernel weight (g) and yield/plant (g). Statistical analysis showed significant variation among maize genotypes. Considering plant height, ear length, ear diameter, ear height, number of kernels/ear and yield/plant BHM-7 was observed as the best one. Among all the traits higher phenotypic coefficient of variation and genotypic coefficient of variation were observed for yield/plant. Genetic advance was highest for 1000-kernel weight followed by number of kernels/ear. The correlation study revealed only two positive significant associations: plant height with yield/plant and ear diameter with ear length. Nine genotypes were grouped into three clusters. These all clearly indicated the presence of ample genetic diversity among maize genotypes which can be exploited in future breeding program for better utilization of maize germplasm.Res. Agric., Livest. Fish.2(1): 53-61, April 2015

Aims: The genetic improvement of garlic can be achieved by biotechnological manipulations as breeding in this vegetatively propagated crop is limited. The current research was conducted with a view to develop an efficient in vitro regeneration protocol for four local garlic accessions namely, G121, G122, G123 and G124. Place, Duration and Design of Study: The experiment was conducted in the Tissue Culture Laboratory of the Department of Genetics and Plant Breeding, Bangladesh Agricultural University during the period from June 2013 to June 2014 using three-factorial experimental design. Methodology: The root tips, basal disc and leaf base were cultured in MS medium supplemented with 2, 4-Dichlorophenoxyacetic acid (2, 4-D) alone, and with both 2, 4-D and 6-Benzylaminopurine (BAP) together for callus induction and the later for subsequent sub-culturing and proliferation of callus. MS medium supplemented with 1-Naphthaleneacetic acid (NAA) and BAP was used for plantlet regeneration. Results: The percentage of callus induction increased with the increase in the concentration of 2,4-D, starting from 0.5 mg L^-1 till 2.0 mg L^-1 and declined with further increase in the concentration of 2,4-D. The MS medium supplemented with 2,4-D and BAP showed higher percentage of callus induction and callus proliferation compared to that of with 2,4-D alone. The highest percentage of callus induction was observed in the genotype G124 from the explant basal disc (85%) and in the genotype G121 from the explant leaf base (80%) with 2.0 mg L^-1 2,4-D and 2.0 mg L^-1 BAP. MS medium supplemented with 2 mg L^-1 2,4-D + 0.5 mg L^-1 BAP showed highest percentage of callus proliferation (90%) in almost all the genotypes. The highest percentage of plantlet regeneration were observed in the genotype G124 for the explants basal disc (63.33%) in MS medium supplemented with 2 mg L^-1 NAA + 1 mg L^-1 BAP. The survival rate of the plantlets after acclimatization varied from 40% (in G123) to 70% (in G121). Conclusion: The optimized protocol of plant regeneration from local garlic accessions will be useful for any future garlic improvement programs using biotechnological means.

Aims: The purple leaf blotch (PLB) disease, for which there is no released resistant variety in Bangladesh, causes loss in production of onion in every year. The mutants of a released variety, BARI Piaz-2 has shown to possess resistance against PLB which is yet to be characterized at molecular level. An easy and simple molecular detection technique of the gene responsible for this disease will be of great use in future. The present study was thus carried out to molecularly characterize four mutant lines of onion using Simple Sequence Repeat (SSR) marker to detect the presence or absence of PLB gene conferring resistance against purple blotch disease in onion. Place and Duration of Study: The research was carried out during the period from March, 2013 to April, 2014 in the Biotechnology Laboratory of Bangladesh Institute of Nuclear Agriculture (BINA) in Mymensingh, Bangladesh. Methodology: DNA was extracted from the vigorously growing fresh leaf samples of 25 days old seedlings of four mutant lines namely, BP₂-75/2, BP₂ -100/1, BP₂-100/2 and BP₂-100/12 of onion using CTAB method. The molecular characterization was done using two sets of SSR markers, namely MatK-1RKIM-f/MatK-3FKIM-r and rbcLa-F/rbcLa-R. Results: All the four mutant lines showed clear band for the primer MatK-1RKIM-f/MatK-3FKIM-r which indicates the presence of PLB gene inferring resistance against purple blotch. Clear band was also observed with the marker rbcLa-F/rbcLa-R in all mutant lines except BP₂-100/12 indicating absence of PLB gene in BP₂ -100/12 which inferred susceptibility against purple blotch of onion. An unknown allele was also detected in this experiment which may be either linked with the PLB gene or a candidate gene which triggers the PLB gene responsible for purple blotch of onion. Conclusion: Both the primers seemed to be effective in detecting the presence or absence of PLB gene in the studied mutant lines of onion variety BP₂. However, more number of primers should be tested for effective screening of diverse germplams that will be helpful in designing any future breeding programs.

Phenotypic plasticity is the ability of an individual genotype to express phenotype variably in different environments. This study investigated the plasticity of yield-related traits of bread wheat by utilising 225 doubled haploid (DH) lines developed from cv. Westonia and cv. Kauz, through two field trials in Western Australia. Plasticity was quantified via two previously published methods: responsiveness to varying ecological conditions and slopes of reaction norms. The spikelets/spike was the most plastic trait, with an overall plasticity of 1.62. The least plastic trait was grain protein content, with an overall plasticity of 0.79. The trait hierarchy based on phenotypic plasticity was spikelets/spike > thousand kernel weight > seed number > seed length > grain yield > grain protein content. An increase in yield plasticity of 0.1 was associated with an increase in maximum yield of 4.45 kg ha⁻¹. The plasticity of seed number and grain protein content were significantly associated with yield plasticity. The maximal yield was positively associated with spikelets/spike and grain yield, whereas it negatively associated with grain protein content. In contrast, the minimal yield was found to be negatively related to the plasticity of spikelets/spike and the plasticity of grain yield, whereas it was not related to grain protein content plasticity. Seed number and seed length exhibited plastic responses at the higher fertilisation state while remaining relatively stable at the lower fertilisation state for the wheat DH population. The finding of the current study will play a key role in wheat improvement under the changing climate. Seed length and seed number should be the breeding target for achieving stable yield in adverse environmental conditions.