Acalypha (Euphorbiaceae) consists of approximately 450 species. Acalypha indica L. is a common annual herb (1-3 ft high). The plant develops a peculiar terminal monocarpellary female flower at the tip of inflorescence axis, it is known as allomorphic flower. Actually, the species produces two kinds of female flower, viz. the allomorphic flower and lateral, tricarpellet regular euphorbiaceous (female) flower. Interestingly, two kinds of female flowers exhibit two opposite mode and direction of evolutionary trends. The lateral flower shows regressive evolutionary trend while the terminal flower shows the trend of progressive evolution. The allomorphic flower, from either progressive or regressive view, stands in a different state of evolution from other flowers; this is a case of heterobathmy. And, both kinds of flowers are under neutral selection pressure, and the development of unicarpellary flower in this Euphorbiacean member is a kind of neutral evolution.

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Chromosome characterization of Achillea fragrantissima (Forssk) Sch. was investigated to find distribution of the A-T heterochromatin rich regions and both 5S and 45S rDNA’s by DAPI and FISH. The chromosomes DAPI-stained showed DAPI-positive bands on interphase and metaphase chromosome complement, of which fifteen chromosomes had terminal bands on both arms and three chromosomes had single positive DAPI bands on a single arm. Applying FISH simultaneously by using the digoxigenin labeled pTa71 probe of 45S rDNA and biotin labeled probe of 5S rDNA on the mitotic chromosomes showed four red and yellow colored signals that were four red terminals and four yellow interstitials obtained after hybridization of the probes with metaphase chromosomes.

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Two mulberry varieties namely, S13 and Kollegal have been analyzed for micro-morphology and meiotic studies. These varieties exhibited considerable variations in height, internodal distance, leaf texture and stomata frequency. Based on chromosome number, chromosomal configurations and other meiotic behavior, both the varieties are diploids with 2n=28 chromosome numbers. Meiosis showed marginal differences. Various meiotic abnormalities like occurrence of one large chromosome, stickiness, clumping, non separation, unequal separation, laggards, precocious movement and unoriented chromosomes have been observed.

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A karyomorphological study was made among three species of Zygophyllum grown in the Mediterranean type ecosystem located in Upper Egypt. The chromosome numbers of Zygophyllum species were listed as follows: 2n=10 of Z. album, 2n=16 of ,Z. coccineum and 2n=22 that was new count to Z. simplex.

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Heavy metals are genotoxic and carcinogenic in nature. Chromosomal plant assay is an important tool used for the evaluation of genome damaging property of pollutants above the optimum level. The paper presents the results of a study concerning the influence of different concentrations of Pb and Cd on cytological and chromosomal level in root tip cells of Vicia faba L. The results revealed the specific variations in chromosomal behavior of root tip cells of Vicia faba L. depending on the nature of metals and their concentrations used for the seed treatment. The experimental study assesses the percentage of total active mitotic index and chromosomal abnormalities in the root meristems of Vicia faba L. at control and different doses of heavy metals. It was observed that a lower mitotic index and a higher frequency of chromosomal aberrations were established at all the doses of heavy metals as compared to control ones. An inverse relationship between the active mitotic index and doses of heavy metals was scored. The chromosomal abnormalities comprising C-mitosis, scattering, stickiness, precocious movement, laggard, bridges etc. were frequent along with the increasing doses of heavy metals. The treatment has been carried out at four different concentrations (2ppm, 4ppm, 6ppm, 8ppm) of both the metal salts (PbCO3 and CdCl2) at room temperature for 3 hrs. The results proved that Pb has more genotoxic potentialities than Cd.

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The present investigation deals with the mutagenic effects of six doses of γ rays viz., 15 kR, 30 kR, 45 kR, 60 kR, 75kR and 90 kR on pollen fertility and meiosis in M1 generation of two varieties of Isabgol (Plantago ovata Forsk.) i.e., var. Mayuri and var. Niharika. These studies were carried out in control as well as in treated population of both the varieties. During the meiotic studies various types of chromosome aberrations were identified at different stages of meiosis in all the doses of γ rays. These anomalies were observed to be dose dependent and positively correlated with the doses of γ rays applied in both the varieties. The frequency of meiotic aberrations was maximum at metaphase followed by anaphase and telophase stages. Pollen fertility had also shown a gradual decrease with an increase in doses of γ rays in both the varieties. These collective observations had indicated that γ rays are more effective in var. Mayuri as it produced more chromosomal aberrations in var. Mayuri in comparison with var. Niharika, and equally suggested that var. Mayuri is more sensitive to the γ rays than the var. Niharika.

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