M – O

Male gametocide
The chemical which induces male sterility artificially is called as male gametocide.
Male Sterility
Male sterility refers to either absence of pollen grain or if present it is non-functional.
Manufactured seed
Manufactured seed is encapsulated plant propagule (somatic embryo / shoot bud) in a suitable matrix, containing substances like nutrients, growth regulators, herbicides, insecticides, fungicides and mycorrhizae which will allow and help it to grow into a complete plantlet.
Mass selection
Mass selection is the creation of mixture of different lines.
Meiocytes are the cells in which meiosis takes place.
Meiosis is a kind of cell division in which cell is permanently transformed into a gamete and cannot divide again until fertilization.
Meiotic crossing over
When crossing over occurs during meiosis, it is called as meiotic crossing over.
Mendel is known as father of genetics.
A meristem (meristem culture) is a group of undifferentiated plant cells (found at growth tips) which can undergo divisions to form all types of tissues.
Metacentric chromosome
Chromosome with centromere at center is called as metacentric chromosome.
Micropropagation is the growing of plants from meristematic tissue or somatic cells of superior plants on nutrient suitable media under controlled aseptic physical conditions.
Microspore culture
In Microspore culture haploid plants are obtained from isolated pollen grains.
Mitosis is the process by which a single cell divides and produces two daughter cells, each containing the same number of chromosomes and genetic content as that of the parent cell.
Mitotic crossing over
When crossing over occurs in chromosomes of somatic cells of an organism during mitotic cell division, it is called as mitotic crossing over.
Modifier or modifying gene
Modifier or modifying gene is the gene which affects or alters the expression of some other non-allelic gene.
Monocentric chromosome
Chromosome with one cetromere is called as monocentric chromosome.
Species with one cotyledon are called as monocotyledonous species or monocots or Monocotyledons.
Monohybrid is the progeny of a cross between two individuals which differ in only single character (contrasting character) i.e. heterozygous for one gene.
Monohybrid cross
A cross between two individuals which differ in only single character (contrasting character) i.e. heterozygous for one gene.
Individuals with a single copy of a single genome are called as monoploids.
Monoploidy (monoploids) denotes presence of a single copy of a single genome
Monosomy is a condition where one chromosome is missing from the somatic chromosome complement
Multiline breeding
Procedure followed to develop multiline variety is called as multiline breeding.
Multiline variety
Multiline variety is a mixture of several pure lines of similar phenotype(height, seed color flowering time, maturity time and various other agronomic characteristics) but have different genes for the character under consideration the disease resistance means these are isogenic lines.
Multiple Alleles
In the case of multiple alleles, certain traits have more than two alleles that are found in a population. But each individual only has two….read more on multiple alleles
Multiple allelic series
The set of alleles is referred as multiple allelic series.
Mutational heterosis
Lethal (mostly), recessive, adaptively unfavorable mutants are either eliminated or sheltered by their non-lethal, dominant and adaptively superior alleles in cross pollinated crops. This is termed as mutational heterosis.
Narrow sense Heritability
Ratio of additive variance to the total or phenotypic variance s called as narrow sense heritability
Natural selection
The process because of whose existence some organisms live more and reproduce efficiently as compared to the others is called as natural selection.
Non-endospermic seed
Seeds with no endosperm (a special food storage tissue) at maturity are called as non-endospermic seed.
Nucleolar Organizer
Nucleolar organizer are some parts of secondary constrictions which contain the genes coding for 5.8s, 18s and 28s rRNA.
Nucleus seed
Nucleus seed is the initial amount of pure seed of improved variety or notified variety or parental lines of a hybrid produced under supervision of the evolver of that variety.
Nullisomy is a condition where one pair of chromosome is missing from the somatic chromosome complement
Often Cross-pollination
In many self pollinating species, cross pollination may occur up to 5% or even reach to 30%, it is called as often cross-pollination.
Organ culture
In organ culture specific organ is excised and cultured on a suitable growth nutrient medium under aseptic and controlled physical conditions.
When progeny exceeds parental limits for any character it is called as over-dominance.