To understand plant evolution and diversification, information regarding chromosome number and meiotic behavior is imperative. The present study was carried out to determine the chromosome count, ...meiotic behavior, pollen fertility, and seed set of a medicinally important plant Peganum harmala. Two cytotypes, diploid and tetraploid are growing in western Himalaya; the diploid cytotype (2n=2x=24) is growing in Kashmir Himalaya, and the tetraploid (2n=4x=48) in Trans Himalaya, Ladakh. Chromosomes pair into perfect bivalents and segregate normally during anaphase-I and II of pollen mother cells. Pollen fertility ranged from 89.97 to 90.46% in the diploid cytotype and 88.0 to 90.0% in the tetraploid cytotype. The cytotypes identified can be exploited for restoration ecology, conservation, and sustainable development.
Apple (
Malus × domestica
) is the third important fruit in terms of production and consumption worldwide. Apple scab caused by
Venturia inaequalis
is the most devastating disease of apple. In the ...apple-growing regions, many fungicides are sprayed to control the disease leading to increase in the production cost. Development of scab-resistant cultivars is the long-lasting solution to control the disease. In apples, more than 20 major scab resistance genes have been identified in various cultivars and few wild relatives. Of all these genes,
Rvi6
derived from
Malus floribunda
has been most extensively used in different breeding programs. Gene for gene interactions of these resistance genes with the avirulence genes from
V. inaequalis
have been understood in many cases.
QTL-
based polygenic resistance has also been characterized in apple. Nucleotide Binding Site Leucine-Rich Repeats (NBS-LRR) have been identified from the apple genome and many of them have been characterized from the scab resistance region. Molecular markers associated with most of the major scab resistance genes have been identified and their position has been mapped on different linkage groups. Marker-assisted selection (MAS) can be helpful in speeding up and accurately identifying the scab-resistant parents and progeny. Pyramiding of several major resistance genes can be undertaken for more durable resistance against apple scab. The present paper reviews the
Malus-Venturia
pathosystem, current status of knowledge about scab resistance genes, and their application in breeding against apple scab.
Cytological effects of Endosri-ES (endosulfan), Nuvan-NU (dichlorvos), and Kvistin-KS (carbendazim) were evaluated on mitotic and meiotic cells of
Allium cepa
. Test concentrations were chosen by ...calculating EC
50
values of formulated ES, NU, and KS, which turned to be 60, 200, and 500 ppm (parts per million), respectively. Cytological studies were undertaken on root meristem cells of
A. cepa
using EC
50
, 1/2 × EC
50
, and 2 × EC
50
of these pesticides for 24 and 48 h. Similarly, a meiotic study was conducted by applying the pesticides at the aforesaid concentrations from seedling to bud stage. A set of onion bulbs exposed to tap water was run parallel for negative control and maleic hydrazide (112.09 ppm) as positive control. During the study period, mitotic index (MI) decreased at all the pesticide concentrations compared to the negative control. Among various chromosomal aberrations, chromatin bridges, breaks, stickiness, laggard, vagrant chromosomes, fragments, C-mitosis, multipolarity, ring chromosome as well as micronuclei were observed in mitotic preparations. In contrast, meiotic aberrations revealed comparatively less frequency of chromosomal aberrations and the most frequent were lagging chromosome, stray bivalents, secondary association, chromatin bridge, disturbed anaphase, and stickiness. Comparative analysis of the pesticides showed that NU was highly toxic to plant cells than KS, while as ES showed intermediate effects between the two. Further, our study revealed that all the three pesticides produce genotoxic effects which can cause health risks to the human populations.
Graphical Abstract
ᅟ
The oxidoreductase NQO1 plays a prominent role in maintaining the cellular homeostasis. NQO1 is mainly a cytosolic enzyme which catalyzes the metabolism of quinones and is present in almost all ...tissue types providing protection against different stresses including xenobiotics, oxidants, UV light, and ionizing radiation. This enzyme is overexpressed in many cancerous tissues and its function in carcinogenesis remains unclear. Due to the relative lack of information on the role of NQO1 in melanoma pathogenesis, we attempted to determine the expression and basic function of NQO1 in melanoma cell proliferation. We found that NQO1 is overexpressed in most melanoma cell lines with respect to melanocytes. Furthermore, the expression of this oxidoreductase significantly induces cell cycle progression by upregulating the expression of cyclins A2, B1 and D1, leading to the proliferation of melanoma cells. Our results also indicate that NQO1 is an upstream regulator of NF-κB p50, a factor linked to melanoma progression and poor patient prognosis. Interestingly, we found that NQO1 stabilizes the transactivator BCL3, which in turn upregulates NF-κB p50. More importantly, our results also indicate that NF-κB p50 correlates with the expression of NQO1 and mediates its role in the proliferation of melanoma cells.
In order to meet the growing human food and nutrition demand a perpetual process of crop improvement is idealized. It has seen changing trends and varying concepts throughout human history; from ...simple selection to complex gene-editing. Among these techniques, random mutagenesis has been shown to be a promising technology to achieve desirable genetic gain with less time and minimal efforts. Over the decade, several hundred varieties have been released through random mutagenesis, but the production is falling behind the demand. Several food crops like banana, potato, cassava, sweet potato, apple, citrus, and others are vegetatively propagated. Since such crops are not propagated through seed, genetic improvement through classical breeding is impractical for them. Besides, in the case of polyploids, accomplishment of allelic homozygosity requires a considerable land area, extensive fieldwork with huge manpower, and hefty funding for an extended period of time. Apart from induction, mapping of induced genes to facilitate the knowledge of biological processes has been performed only in a few selected facultative vegetative crops like banana and cassava which can form a segregating population. During the last few decades, there has been a shift in the techniques used for crop improvement. With the introduction of the robust technologies like meganucleases, zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR) more and more crops are being subjected to gene editing. However, more work needs to be done in case of vegetatively propagated crops
Saffron (Crocus sativus L.) is triploid (2 n = 3x = 24, x = 8), which limits its improvement through crop breeding programs. This study was initiated to induce hexaploidy with the intent of restoring ...sexual stability in saffron. Corms were treated with colchicine concentrations of 0.0%, 0.025%, 0.05%, and 0.1% for 3-h, 6-h, and 9-h. A total of 16 in-vitro shoots showed signs of polyploidization. These colchiploid shoots showed slow but robust growth and produced large-sized cormlets (6.0 g) compared to the control (2.8 g). Leaf epidermal cell morphology, stomatal size and density showed evidence of polyploidization. Hexaploidy (2 n = 6x = 48) was confirmed by root-tip cytology. The hexaploid corms germinated but could not establish in the field. We were able to develop a protocol for in-vitro induction of hexaploidy in C. sativus, but the subsequent growth of hexaploid corms in the field remains a major challenge in restoring the sexual stability in saffron.
Detailed characterization and documentation of apple genetic resources are crucial for genetic amelioration and germplasm management. This study was carried out to fill the missing gap in information ...on the genetic diversity of cultivated apple (
Malus
×
domestica
Borkh.) germplasm maintained in different orchards and fruit nurseries in different areas of the North Kashmir region. In this study, 62 genotypes collected from the North Kashmir region were screened using ten microsatellite markers. Allelic data were used to elucidate the population structure, genetic relationships, and molecular variance to define the genetic structure of the collection of diverse apple genotypes. A total of 77 alleles were amplified with an average polymorphism percentage of 87.5%, polymorphic information content (PIC) of 0.71, and resolving power (RP) of 3.58. The average genetic diversity indices observed for number of alleles (Na) = 1.67, effective number of alleles (Ne) = 1.47, Shannon’s information index (I) = 0.43, expected heterozygosity (Ho) = 0.29, and unbiased heterozygosity (µ He) = 0.3 per assay indicated a moderate level of genetic diversity. Based on Jaccardʼs similarity coefficient, a UPGMA dendrogram, and principal coordinate analysis, a widespread dispersal of genotypes into three sub-clusters showing a high degree of genetic variability within the groups was obtained. STRUCTURE analysis divided the collection into two (
K
= 2) sub-populations that were more or less grouped on the basis of traditionally cultivated and recently introduced genotypes mixed with a few indigenous genotypes. Analysis of molecular variance (AMOVA) showed significant variation within the populations (81%), indicating that the genotypes were the primary source of wide variation and that there was a limited genetic exchange between the genotypes, which aligns with the findings of the cluster analysis. The apple germplasm analyzed in the North Kashmir region represents an important source of genetic diversity, which can contribute significantly to germplasm management and future apple breeding programs both inside and outside the region.
Buckwheat has tremendous nutraceutical potential owing to its rutin and quercetin content. The aim of this study was to optimise and validate an analytical method for separating and quantifying these ...two flavonoids from it. Factors, such as range, linearity, precision, accuracy, limit of detection and limit of quantification, were evaluated for the two compounds using high performance liquid chromatography. On the basis of resolution and symmetry, mobile phase consisting of methanol and methanol:water:acetic acid in the ratio of (100:150:5), flow rate 1.3 ml/min and column temperature 30 °C were found to be optimal analytical conditions. Calibration curves exhibited good linearity with correlation coefficient of 0.995 & 0.9907 over the range 60–180 μg/ml & 2–10 μg/ml for rutin and quercetin respectively. LOD and LOQ values for rutin and quercetin were 6.36, 0.58 and 19.28, 1.77 μg/ml respectively. Recovery values of 96–100.8% confirmed that the method was accurate for rutin and quercetin analysis. This validated method was successfully used to analyse rutin and quercetin in leaves and seeds of buckwheat plant.
The collection and characterization of apricot germplasm is an important step for its utilization, conservation, and breeding programs. In the present study, the genetic diversity and population ...structure of 106 accessions of apricot including 82 indigenous and 24 exotic accessions collected from various geographical locations of Jammu and Kashmir, India were evaluated using 14 inter simple sequence repeat markers. The PCR amplification produced 365 loci of which 356 (97.53%) were polymorphic. The average number of alleles, effective number of alleles, expected heterozygosity, Shannon’s information index indicated high level of genetic diversity in the collected apricot accessions, and the polymorphism information content (0.82) revealed that these markers were highly polymorphic. The results of UPGMA dendrogram and model-based STRUCTURE analysis clearly divided the 106 apricot accessions into two main groups; one group included the 78 accessions of Kashmir province and the other included 28 accessions of Jammu province indicating the distinction of two genetic pools of apricot in the region. Nonetheless, PCoA also revealed a similar grouping of accessions except few exotic accessions that formed a small separate group. Moreover, analysis of molecular variance showed high genetic variation within the population (67%) and low among the population (33%). To our knowledge, this study represents the first comprehensive report on the ISSR based genetic diversity, relationship, and the structure of apricot accessions of Jammu and Kashmir. Further, the results of the present study will assist in efficient utilization, conservation, and MAS based breeding programs of apricot.
Rising global temperatures, changing precipitation patterns, spread of insects and diseases, and slow development of crop varieties acclimatized to new environments have produced a food crisis ...situation in some developing countries. Although transgenic technologies came to the rescue, they faced numerous hurdles on the journey to reach the farm soil, which has necessitated innovation of out-of-the-box technologies for crop improvement. One such non-transgenic method, which exploits the ever-increasing sequence data and combines it with traditional and modern methods to induce and extract mutants, is Targeting Induced Local Lesions IN Genomes (TILLING). With the success of TILLING in monocots, dicots, autopolyploids, allopolyploids, and triploids, we expect this technique to help develop many mutant crop varieties in the next few decades. We trust this review will be useful for researchers engaged in crop improvement around the globe.
