Durum Wheat Seeds Research Articles

Response to X-rays of dormant and non-dormant seeds of Triticum durum desf

The X-ray sensitivity of dry seeds of durum wheat at different levels of dormancy was examined. Two doses of X-ray exposures (1000 and 5000 R) were utilized and analysis was carried out on cells from root to tip meristems of seeds allowed to germinate on moistened filter paper for different times. The results showed that the 1000 R dose did not increase the spontaneous chromosome damage in deep dormant seeds, while inducing a 100% increase in chromosome damage in lightly dormant and in non-dormant seeds. The deep dormant seeds irradiated with 5000 R showed a chromosome damage lower than that of both lightly dormant and non-dormant seeds. The chromosome damage was of chromatid type (B′) at 1000 R, irrespective of the physiological condition of the seeds. On the contrary, the lightly dormant or non-dormant seeds irradiated with 5000 R showed both chromatid and chromosome (B″) damage; the deep dormant seeds exhibited B′ damage only. The lack of B″ damage in root meristems from deep dormant seeds is likely to be due to ( i) the physiological state of seeds which causes a slow germination and a possible delay of mitosis initiation at germination, ( ii) a more efficient repair process or a greater radiation resistance bound to the metabolic condition of the deep dormant seeds.

Response to X-rays of dormant and non-dormant seeds of Triticum durum desf

The X-ray sensitivity of dry seeds of durum wheat at different levels of dormancy was examined. Two doses of X-ray exposures (1000 and 5000 R) were utilized and analysis was carried out on cells from root to tip meristems of seeds allowed to germinate on moistened filter paper for different times. The results showed that the 1000 R dose did not increase the spontaneous chromosome damage in deep dormant seeds, while inducing a 100% increase in chromosome damage in lightly dormant and in non-dormant seeds. The deep dormant seeds irradiated with 5000 R showed a chromosome damage lower than that of both lightly dormant and non-dormant seeds. The chromosome damage was of chromatid type (B′) at 1000 R, irrespective of the physiological condition of the seeds. On the contrary, the lightly dormant or non-dormant seeds irradiated with 5000 R showed both chromatid and chromosome (B″) damage; the deep dormant seeds exhibited B′ damage only. The lack of B″ damage in root meristems from deep dormant seeds is likely to be due to (i) the physiological state of seeds which causes a slow germination and a possible delay of mitosis initiation at germination, (ii) a more efficient repair process or a greater radiation resistance bound to the metabolic condition of the deep dormant seeds.

Polyamines and RNA content in wheat embryos from seeds of different age

Abstract The content of polyamines and RNA in isolated embryos from dry resting seeds of durum wheat has been determined. This, with the aim to investigate the variations of the polyamines and RNA amounts during the ageing process and to correlate them with the loss of germination capacity of the seeds. The results showed that the total polyamines increase while the RNA content decreases during the ageing of the embryos. Since no great difference exists as to the polyamine content between the embryos from seeds capable and incapable to germinate, it appears to be lacking a close relationship between the polyamine content and the germination capacity of the examined seeds. The decrease of the RNA content and the corresponding increase of the polyamine-N/RNA-nucleotide ratio, seem to suggest that the loss of germination capacity of the wheat seed could be related to impaired regulation properties during the ageing process.

Ageing of isolated embryos and endosperms of durum wheat: An analysis of chromosome damage

Abstract Embryos (EM) and endosperms (END) were isolated from durum wheat seeds and aged separately for 3 years. Analysis of chromosome damage was carried out on root tip meristems of transplants in which aged (a) embryos and/or endosperms were used. The aim of the experiments was to investigate the ageing process when embryos and endosperms age separately and to evaluate the possible influence of the endosperm during storage of the seed. The results obtained indicate that ( i ) both aged embryo and endosperm produce mutagenic substances capable of inducing nuclear damage in the radicle meristem and ( ii ) age-induced damage in the embryo is not the consequence of endosperm ageing. The relationships between chromosome damage produced by aged embryos and endosperms in the transplants are discussed.

Ageing of isolated embryos and endosperms of durum wheat: An analysis of chromosome damage

Embryos (EM) and endosperms (END) were isolated from durum wheat seeds and aged separately for 3 years. Analysis of chromosome damage was carried out on root tip meristems of transplants in which aged (a) embryos and/or endosperms were used. The aim of the experiments was to investigate the ageing process when embryos and endosperms age separately and to evaluate the possible influence of the endosperm during storage of the seed. The results obtained indicate that (i) both aged embryo and endosperm produce mutagenic substances capable of inducing nuclear damage in the radicle meristem and (ii) age-induced damage in the embryo is not the consequence of endosperm ageing. The relationships between chromosome damage produced by aged embryos and endosperms in the transplants are discussed.

Further observations on embryo-endosperm relations in irradiated water soaked seeds of durum wheat

Further observations on embryo-endosperm relations in irradiated water soaked seeds of durum wheat

The mutagenic effect of the irradiated endosperm in water-soaked seeds of durum wheat

The mutagenic effect of the irradiated endosperm in water-soaked seeds of durum wheat

The chromosome breaking effect of the irradiated endosperm in water-soaked seeds of durum wheat

The chromosome breaking effect of the irradiated endosperm in water-soaked seeds of durum wheat

Radiation induced asynaptic mutations in durum wheat (Triticum durum DESF.)

The cytological behaviour and the inheritance of two asynaptic mutations independently obtained by neutron treatment of durum wheat seeds of var. Cappelli and Aziziah are considered. Mutant individuals of both lines have normal morphology, but are completely sterile. Analysis of chromosome behaviour at the several stages of PMC meiosis has been thoroughly accomplished in mutant progenies of both varieties during two subsequent generations. A completely random chromosome disjunction was found at anaphase I, together with multipolar spindles, laggard chromosomes etc. At meiotic second division a large amount of abnormalities were found, as a consequence of previous asynapsis and irregular polarization. Some differences in cytological behaviour were found between the asynaptic mutants of Cappelli and the asynaptics of Aziziah. - Genetic analysis demonstrated that both mutations behave as monogenic recessives.

Ricerche Sulle Sostanze Alchilanti Mutagene

Abstract Researches on alkylating chemicals mutagens (method of treatment with diethyl sulfate. — The problem of the treatment of seeds with alkylating agents, belonging to the categories of alkylsuphonic and sulphuric esters, was investigated from a chemical and methodological viewpoint. After a determination of the hydrolisis constants and of the activation energies of some compounds, diethylsulphate, undergoing hydrolisis most rapidly and — consequently — being the least appropriate for use in solution, was chosen for treatment of durum wheat seeds (cv. « Cappelli »). Using treatments of different durations with solutions of different concentrations under several temperature conditions, the amounts of diethylsulphate and of ethylsulfuric acid (one of the hydrolisis products) absorbed per seed in each treatment were calculated. In addition, the effect of the two fractions on seed germinability was studied. Since the threshold value of the germination inhibiting effect of ethylsulfuric acid was fixed at ...