Effect of plant growth regulators on callus induction and plant regeneration in tuber segment culture of potato (Solanum tuberosum L.) cultivar Diamant

The present study was conducted to investigate the effects of different concentrations and combinations of growth regulators on callus induction and plant regeneration of potato (Solanum tuberosum L.) cultivar Diamant. The tuber segments were used as explants and cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of -naphthalene acetic acid(NAA), 2,4-Dichlorophenoxy acetic acid (2,4-D), benzyl adenine (BA) and thidiazeron (TDZ) alone and 2,4-D in combinations with BA for callus induction. The best degree for callus formation (6.0) wasobtained on MS medium supplemented with 2,4-D alone at 3.0 mg/l or 2,4-D in combination with BA both at 2.0 mg/l. MS media supplemented with different levels of BA and TDZ were employed for shootregeneration. MS medium containing 5.0 mg/l TDZ was the best for days to shoot initiation, the highest percentage of callus with shoot (81%) and highest number of shoot per callus (3.4). Callus derivedshoots were rooted most effectively in half-strength MS medium containing 0.5 mg/l IBA. The success of plant tissue culture for in vitro culture of potato was encouraged by acclimatization of the plantlets inthe greenhouse conditions. Regenerated plants were morphologically uniform with normal leaf shape and growth pattern

Callus formation and organogenesis of tomato (Lycopersicon esculentum Mill, C.V. Omdurman) induced by thidiazuron

In vitro culture response was assessed in tomato (Lycopersicon esculentum Mill. c. v. Omdurman) for optimum callus induction and plantlet  regeneration. Callus induction was achieved within seven to ten days directly on the cut surfaces of both hypocotyls and cotyledon explants cultured on Murashige and Skoog (MS) basal medium supplemented with -naphthalene acetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), Thidiazuron (TDZ) and benzyl adenine (BA) alone or in differentcombinations, but not in hormone free-medium. The highest callusing index (5.3) was obtained on hypocotyls explants cultured on MS medium supplemented with NAA at 0.5 mg/l followed by an index of 5.2 obtained from the same explant by using 0.1 mg/l NAA in combination with BAP at 0.5 mg/l. However, for the cotyledon explants, the highest callusing index (4.7) was obtained on MS medium supplemented with NAA at either 2.0 or 3.0 mg/l. After 8 weeks of culture, organogenesis was observed only on the explants cultured on medium containing different concentrations of TDZ alone or in combination with BAP. The best shoot formation (93%) was obtained for cotyledon explant callus induced on MS medium containing TDZ in combination with BAP both at 0.5 mg/l. The highest number(6) of shoot per explant was obtained when cotyledon explant callus was sub cultured on MS medium supplemented with 3.0 mg/l TDZ. Plain half strength of MS was found to be the best rooting medium, however, addition of IAA at 1.0 mg/l and IBA at 2.0 mg/l were found essential to induce highest number of roots (22.1 ± 0.9) and longer roots (11.0 ± 0.3 cm), respectively. This protocol would be useful to create somaclonal variation and utilize transgenic approaches for varietal improvement of tomato

Assessment of genetic diversity in Sudanese maize (Zea mays L.) genotypes using random amplified polymorphic DNA (RAPD) markers

The randomly amplified polymorphic DNA (RAPD) molecular markers were used to assess genetic diversity in 27 Sudanese maize genotypes. Ten primers were used, resulting in the amplification of 59 fragments, of which 53 (89.33) were polymorphic. The maximum number of fragment bands (10) were produced by the primer A-1 with 100% polymorphism, while the minimum numbers of fragments (3) were produced by the primer OPA-20. Using the unweighted pair group method with arithmetic averages (UPGMA) method, the genetic associations obtained showed three distinct heterotic groups. The high rate of polymorphism between genotypes revealed by RAPD markers indicated that the method is efficient to analyze genetic divergence and can be used to establish consistent heterotic groups between maize genotypes.Key words: Randomly amplified polymorphic DNA (RAPD) markers, DNA polymorphism, maize genetic diversity

Random amplified polymorphic DNA (RAPD) marker associated with salt tolerance during seeds germination and growth of selected Acacia senegal provenances

Seed germination and seedling growth of 20 provenances of Acacia senegal were evaluated under salinity conditions. For germination study, seeds irrigated with NaCl in five concentrations had electrical conductivities (EC) of 0 (only distilled water), 2, 4, 6 and 10 dSm-1. Final germination percentage (FG) and germination rate index (GRI) were recorded during 14 days. The result showed significant effect of salinity and provenance on FG and GRI. Seed germination was significantly reduced in all provenances with the increase in NaCl concentrations. Provenance Al Feel (FE, clay+ high rainfall) from Eastern Sudan was more tolerant than the other provenances at seed emergence stage. Greenhouse experiment examined the growth response of 8 provenances A. senegal chosen as the most tolerant provenances at seeds germination study. Potted seedlings aged 3 weeks were irrigated with 0, 4, 6 and 10 dSm-1. Seedling height, root length, shoot dry weight, root dry weight and root/shoot ratio were measured for 4 weeks. Provenances showed a large variability in growth characteristics. No correlation between seed sources (soil type and rainfall) and growth  response was found. However, provenance MH shows tolerance to salt stress at seedling stage. The genetic polymorphism between the provenances was detected by RAPD analysis. Forty four (44) out of 51 bands detected were polymorphic for the provenances of A. senegal and the dissimilarity indices between the studied provenances were less than 39%.Key words: Acacia Senegal, provenance variation, random amplified polymorphic DNA (RAPD) marker, salt tolerance, seed germination, seedling growth

Establishment of in vitro fast-growing normal root culture of Vernonia amygdalina - a potent African medicinal plant

Fast-growing normal root culture of Vernonia amygdalina, a potent African medicinal plant was established from leaf explants of in vitro raised shoot induced from the stem nodal segments on murashige and skoog (MS) medium containing 0.5 mg l-1 6-benzylaminopurine (BA) in combination with 0.5 mg l-1 naphthalene acetic acid (NAA). In vitro raised plantlets were maintained on MS agar medium and sub cultured at 4 weeks interval and used as leaf explant source. Explants were cultured on halfstrengthMS medium supplemented with different concentrations of Indole-3-acetic acid (IAA), indole-3- butyric acid (IBA) and NAA. Basal medium supplemented with IBA at 0.25 and 2.0 mg l-1 and under 16photoperiod condition favoured induction of the longest root (2.7 ± 1.1 cm) and highest number of roots/explant (38.3 ± 1.1) respectively. After 6 weeks well established roots were separated. Fresh root tissue, in amount of a 100 mg were cultured in 50 ml full-strength MS liquid medium supplemented with 2.0 mg l-1 IBA and under continuous agitation (80 rpm). The biomass of root culture was increased to 2.1949 g after 5 weeks of culture. The root culture was maintained up to 6 weeks. The protocoldeveloped in this study provides a basis for adventitious root induction and for further investigation of medicinally active constituents of this elite medicinal plant

Study of genetic diversity in Sudanese sesame (Sesamum indicum L.) germplasm using random amplified polymorphic DNA (RAPD) markers

The random amplified polymorphic DNA (RAPD) markers were used to assess genetic diversity in Sesame indicum (L.). RAPD technique was carried out in a set of 10 sesame germplasm collected from different regions of Sudan. A total of 64 polymorphisms (6.4 polymorphic markers per primer) out of 75 reproducible products (7.5 fragments per primer) were obtained from the 10 primers used. The number of bands per primer ranged from 4 to 13, whereas the number of polymorphic bands ranged from 3 to12, corresponding to 66.6% of the amplification products. Low level of genetic similarity was observed in the collected accessions. Unique bands were observed with the 10 primers. UPGMA clustering resulted in two major groups

Efficient production of transgenic soybean (Glycine max [L] Merrill) plants mediated via whisker-supersonic (WSS) method

The present study was designed to evaluate the transformation efficiency and proof the capability of whisker supersonic (WSS) method as an alternative option for soybean (Glycine max [L] Merrill)transformation. We compared soybean transformation efficiency obtained by WSS-mediated with that of particle bombardment transformation by carrying out molecular analysis of the T0 plants in two independent experiments. For this, we used for both transformation techniques the same genotype, the same plasmid and the same selection method. To assess the efficiency of soybean genetictransformation, we evaluated the efficiency of multi gene transformation by the selection with hygromycin and the expression of green fluorescent protein [sGFP (S65T)] resulted from both techniques. Regenerable embryogenic cells were induced from immature cotyledons of soybean c.v Jack on MSD40 media within 3 weeks then proliferated on FN lite liquid media and engineered with pUHG gene construct through both WSS and particle bombardment-mediated transformation. The pUHG was constructed with pUC 19 and contain the hpt gene conferring resistance to hygromycin as a selective marker and sGFP(S65T) as a reporter gene. Fluorescence microscopy screening after the selection of hygromycin, identified the clearly expression of sGFP(S65T) in the transformed soybean embryos. Stable integration of the transgenes was confirmed by polymerase chain reaction (PCR) andSouthern blot analysis. The average transformation efficiency achieved with WSS was higher than that obtained by particle bombardment and hence it may represent an alternative method for soybeantransformation

Agrobacterium-mediated transformation systems of Primula vulgaris

Background: Genetic transformation is a valuable tool and an important procedure in plant functional genomics contributing to gene discovery, allowing powerful insights into gene function and genetically controlled characteristics. Primulaceae species provide one of the best-known examples of heteromorphic flower development, a breeding system which has attracted considerable attention, including that of Charles Darwin. Molecular approaches, including plant transformation give the best opportunity to define and understand the role of genes involved in floral heteromorphy in the common primrose, Primula vulgaris, along with other Primula species. Results: Two transformation systems have been developed in P. vulgaris. The first system, Agrobacterium-mediated vacuum infiltration of seedlings, enables the rapid testing of transgenes, transiently in planta. GUS expression was observed in the cotyledons, true leaves, and roots of Primula seedlings. The second system is based on Agrobacterium tumefaciens infection of pedicel explants with an average transformation efficiency of 4.6%. This transformation system, based on regeneration and selection of transformants within in vitro culture, demonstrates stable transgene integration and transmission to the next generation. Conclusion: The two transformation systems reported here will aid fundamental research into important traits in Primula. Although, stable integration of transgenes is the ultimate goal for such analyses, transient gene expression via Agrobacterium-mediated DNA transfer, offers a simple and fast method to analyse transgene functions. The second system describes, for the first time, stable Agrobacterium-mediated transformation of Primula vulgaris, which will be key to characterising the genes responsible for the control of floral heteromorphy

Post-Vasectomy Semen Analysis: Optimizing Laboratory Procedures and Test Interpretation through a Clinical Audit and Global Survey of Practices

Purpose: The success of vasectomy is determined by the outcome of a post-vasectomy semen analysis (PVSA). This article describes a step-by-step procedure to perform PVSA accurately, report data from patients who underwent post vasectomy semen analysis between 2015 and 2021 experience, along with results from an international online survey on clinical practice. Materials and methods: We present a detailed step-by-step protocol for performing and interpretating PVSA testing, along with recommendations for proficiency testing, competency assessment for performing PVSA, and clinical and laboratory scenarios. Moreover, we conducted an analysis of 1,114 PVSA performed at the Cleveland Clinic's Andrology Laboratory and an online survey to understand clinician responses to the PVSA results in various countries. Results: Results from our clinical experience showed that 92.1% of patients passed PVSA, with 7.9% being further tested. A total of 78 experts from 19 countries participated in the survey, and the majority reported to use time from vasectomy rather than the number of ejaculations as criterion to request PVSA. A high percentage of responders reported permitting unprotected intercourse only if PVSA samples show azoospermia while, in the presence of few non-motile sperm, the majority of responders suggested using alternative contraception, followed by another PVSA. In the presence of motile sperm, the majority of participants asked for further PVSA testing. Repeat vasectomy was mainly recommended if motile sperm were observed after multiple PVSA's. A large percentage reported to recommend a second PVSA due to the possibility of legal actions. Conclusions: Our results highlighted varying clinical practices around the globe, with controversy over the significance of non-motile sperm in the PVSA sample. Our data suggest that less stringent AUA guidelines would help improve test compliance. A large longitudinal multi-center study would clarify various doubts related to timing and interpretation of PVSA and would also help us to understand, and perhaps predict, recanalization and the potential for future failure of a vasectomy