Green Plant Production Research Articles

Factors affecting anther culturability of recalcitrant barley genotypes

One major problem encountered with cereal anther culture is that some genotypes are low or non-responders to the technique. The objective of this study was to improve anther culture efficiency of recalcitrant barley (Hordeum vulgare L.) genotypes. Reciprocal F1s between the two low responsive cultivars, Morex and Steptoe, were used. These were chosen because doubled haploids (DH) were required from these genotypes for the North American Barley Genome Mapping project. Ficoll 400 at 200 g l(-1) in the induction medium significantly increased green plant production compared to four other media formations containing different gelling/viscosity modifying agents. Cold pretreatment of donor spikes of 28 vs 14 d resulted in an increase in embryoid, total plant and green plant production. Anther culture response in these experiments was little influenced by donor plant growth conditions. Indole-3-acetic acid (1 mg l(-1)) or 1-naphthaleneacetic acid (2 mg l(-1)) in the induction medium did not affect anther culturability or plant regeneration. Based on this research, the negative genotypic effect for doubled haploid production could be diminished, which is desirable for practical application.

Improvement of anther culture methods for doubled haploid production in barley breeding

There is potential to accelerate cultivar development with a doubled haploid system for breeding line production. Anther culture methodology was evaluated for U.S.A. spring barley (Hordeum vulgare L.) breeding applications. Gelrite was found to be an acceptable replacement for ficoll in the induction medium to reduce costs while maintaining embryoid and plant production levels. Beneficial effects of 28 d cold pretreatment of donor spikes for anther culture were confirmed with Pacific Northwest USA barley genotypes. A 3 d mannitol solution pretreatment of fresh anthers was shown to be less effective for green plant production compared to 28 d cold pretreatment of donor spikes. Extended donor spike cold pretreatment from 28 to 42 d did not reduce anther culture productivity. Based on this research, anther culture techniques show promise for economical and convenient application in spring barley breeding.

The Effects of Genotype and Mannitol Pretreatment on High Frequency Androgenesis in Barley

Since the success in induction of barley pollen plants through anther culture was achieved by Clapham in 1973, a great amount of efforts have been further made on the study. In the past 20 years, the green plant production has been increased by 100-fold by improving culture methods and media etc. However, there still exist a lot of theoretical and applied problems, for example, the green plantlet yield per anther for most materials except some

Influence of 2,4-D, IAA, and duration of callus induction in anther cultures of spring wheat

Culture media and environmental factors may significantly influence the yield of haploid plants from anther cultures. Our objectives were to identify a combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and indoleacetic acid (IAA) concentrations which produce the maximum number of haploid plants, and to evaluate the effects of duration in induction medium on calli induction, plant regeneration, and green plant production from anther cultures in spring wheat. Significant ( P ≤ 0.01) plant growth regulator concentration effects (2,4-D and IAA) were observed on the number of calli, green plants and albino plants produced, and on direct plant regeneration. Addition of 2,4-D to the induction medium resulted in significantly ( P ≤ 0.01) higher means for all anther culture components compared to IAA> While addition of 2,4-D significantly ( P ≤ 0.01) reduced plant regeneration, it substantially increased green plant percentage at a 0.3-mg l −1 concentration of IAA. Use of response functions to estimate the maximum effective 2,4-D × IAA combination implied that higher 2,4-D levels in the induction medium should be investigated, and that the optimum hormone combination differs for plant regeneration and green plant percentage. Significant ( P ≤ 0.01) effects of duration on callus induction medium were observed for plant regeneration and green plant percentage.

Genetic control of green plant regeneration from anther culture of wheat

The low percentage of green plants from anther cultures has limited the applications of haploid techniques in cereal breeding programs. The objective of this study was to estimate the genetic control of green plant percentage in wheat anther culture. Reciprocal crosses were made between a spring wheat 'Chris', which produces a high percentage of green plants, and an experimental line WA7176, which produces a low percentage of green plants. The reciprocal crosses were backcrossed with the respective male parents. A second group of reciprocal crosses and backcrosses was made between 'Yecora Rojo' (high green plant producing parent) and 'Edwall' (low green plant producing parent). Anthers from the parents, reciprocal cross, and backcross progeny were cultured to estimate the relative importance of nuclear genes in the control of green plant production. The percentages of green plants derived from the reciprocal crosses were intermediate between the parents and no significant reciprocal differences were detected. Backcrosses of the reciprocal crosses shifted the percentage of green plants towards the male parents. These results indicate that the percentages of green plants from anther culture of the tested genotypes are under the control of nuclear genes and that the genes are predominantly additive. Significant differences (p ≤ 0.05) for green plant percentage as well as for callus induction and plant regeneration were also detected within the parental genotypes. The within-genotype variation for green plant percentage accounted for 24.5 and 34.1% of total variation for the two groups of crosses, indicating the potential for in vitro prescreening to identify specific parental plants to improve anther culture responses.Key words: Triticum aestivum, wheat, anther culture, albinism, inheritance.

Functional properties of ficoll and their influence on anther culture responses of wheat

The effects of ficoll in liquid culture media have been contradictory in previous reports. The objective of this study was to determine the functional properties of ficoll in potato 4 (P4) liquid induction medium and their influence on anther culture responses of wheat. Ficoll addition significantly (p≤0.01) reduced callus production from the anthers of spring wheat cv. Pavon 76. The reduction was directly related to the concentration of ficoll added within the range of 50 to 200 g l-1 medium. Although the addition of ficoll significantly (p≤0.01) increased the percentage of regenerable calli and the ratio of green vs. albino plants, the final yield of green plants per 100 anthers was significantly lower. Consistent results also were obtained with four other spring wheat genotypes (Chris, Butte 86, WA 6916, and Edwall). Ficoll concentration affected the density, viscosity, and osmolality of the liquid media. The higher medium density caused by ficoll addition increased the percentage of floating calli, as well as the percentage of regenerable calli and the ratio of green vs. albino plants. However, the increased medium viscosity by ficoll addition significantly (p≤0.01) reduced callus production. Ficoll addition also increased medium osmolality, which affected callus production by interacting with the sugar concentration of the induction media. Using response functions, the estimated maltose concentration for maximum callus production was 105 g l-1 for the standard P4 media, compared with 68 g l-1 for the ficoll-containing P4 media. These results clearly demonstrate that ficoll addition to the liquid P4 induction medium containing high sucrose concentration (90 g l-1) is deleterious to the maximum production of green plants from wheat anther culture.

Diallel Analysis of Callus Induction and Green‐Plant Regeneration in Rice Anther Culture

Low efficiencies of callus induction and green‐plant regeneration have limited the application of anther culture in breeding programs. This study was conducted to determine the inheritance of callus induction and plant regeneration in rice (Oryza sativa L.) anther culture. Sixteen genotypes derived from a four‐parent diallel mating set of two Japonica cultivars (Taipei 309 and Taipei 177) and two indica cultivars (IR36 and Basmati 370) were evaluated for their callus induction and plant regeneration abilities. For callus induction, the effects of genotype and genotype ✕ medium interaction were significant (P < 0.05). Similarly, genotype and abscisic acid (ABA) level were found to be significant (P < 0.05) for green‐plant production. The japonica cultivars generally had a higher percent callus induction and plant regeneration, and number of calli producing green plants than did the indica cultivars. Similar modes of inheritance were observed for both characters. Combining ability analysis demonstrated the predominance of additive gene effects in the control of both characters with the japonica cultivars having higher combining ability for green‐plant regeneration. Reciprocal effects were not significant (P > 0.05), suggesting the absence of maternal control on the characters. Further analysis showed gene action to be partially dominant with high response being highly recessive and controlled by a few genes. There were no indications of inter‐allelic interaction.

Improved androgenesis of winter cultivars of Triticum aestivum L. in response to low temperature treatment of donor plants

Low temperature growth conditions (10°C day/5°C night) for anther donor plants during four weeks prior to the mid-uninucleate pollen stage improved the anther culture response of seven winter cultivars of Triticum aestivum L. Green plants were obtained from all the cultivars at a mean frequency of 1.5 per 100 anthers. Anthers cultured at 25°C did not yield green plants but at 30°C microspore callus production was increased 25-fold and green plants were regenerated. Albinism occurred in all the cultivars but the degree of expression was genotype dependent. For green plant production, ficoll (10%) medium was superior to liquid or agarose media; the relative production of albinos was decreased eight-fold in Norstar showing that culture conditions can influence and possibly negate this problem.

Diallel analysis of barley anther culture response

The genetics of barley microspore development in culture was examined by means of diallel analysis. The frequency of microspore derived green and albino plant production was shown to be under genetic control. This genotypic limitation to microspore development will limit the application of anther culture techniques to barley breeding programmes. However, significant additive genetic effects were detected for the characters measured and indicate that the frequency of green plant regeneration may be improved by the hybridization of suitable parents. Significant reciprocal differences were also detected and indicate that the direction of the cross is important in determining microspore development. An embryogenic route to green plantlet formation was observed in a number of genotypes in the diallel experiment. The implications of these findings for barley improvement and genetics are discussed.Key words: doubled haploids, barley, anther culture, microspore, embryoid.

Comparison of Anther Culture and Hordeum bulbosum Method for the Production of Doubled Haploid in Winter Barley I. Production of Green Plants

AbstractThe relative response to two‐major techniques of producing haploids in barley – anther culture and the Hordeum bulbosyum method – were compared using seven F1 hybrids from a winter barley breeding programme. Both techniques were Applied to the same plants with the same number of replications.358 viable green plants were obtained from 420 spikes ot donor plants used: 147 through anther culture and 211 through the H. bulbosum method.From the data analysis we found that the response to the two techniques was not significantly different, genotype effect and genotype × technique interaction were highly significant.The possibility of combining the two techniques in a doubled haploid production programme is discussed.

Anther culture of Hordeum vulgare L.: a genetic study of microspore callus production and differentiation

The inheritance of the ability of barley anthers to produce microspore-derived callus in vitro was investigated. The genotypes selected were the two spring cultivars 'Dissa' (D) and 'Sabarlis' (S), the two F1 hybrids (DxS, SxD), the two backcross generations [Dx(DxS), Sx(DxS)], and an F2 generation derived from DxS. From a number of individuals of each generation, the first five spikes were harvested sequentially and after pre-treatment the anthers were removed and placed in culture. Cultures were scored for microspore callus production and plantlet differentiation. Although 'Dissa' gave a significantly higher level of callus production than 'Sabarlis', the overall frequencies of green and albino plant production were higher from 'Sabarlis'. There was no significant difference between reciprocal F1 hybrids. Analysis of variance revealed significant differences in response between the spikes sampled from the plants. This was the major source of variation in the experiment. Spike to spike variation also appeared to be a heritable character.

Solar energy and agriculture

Agriculture stands pre-eminent as the world’s first and largest industry. It is our most basic enterprise, and its products are renewable as a result of ‘farming the sun’. Through the production of green plants, agriculture is the only major industry that ‘processes’ solar energy. The greatest unexploited resource that strikes the earth is sunlight and the green plants are biological sun traps. Each day they store on earth 17 times as much energy as is presently consumed world-wide. The goal of agriculture is to adjust species and cultivars to locations, planting designs, cropping systems and cultural practices to maximize the biological harvest of sunlight by green plants to produce useful products for mankind. Many products of agriculture may be alternatively used as food, feed, fiber or energy. Conflicts over the agricultural use of land and water resources for food, feed or fuel production will arise as resource constraints tighten.

Improved Rate of Callus and Green Plant Production from Rice Anther Culture Following Cold Shock1

Rice (Oryza sativa L. subsp. japonica) panicles containing pollen at the G1 G2, early binucleate, and late binucleate stages of development were subjected to 5, 10, and 13 C temperatures for 3, 7, 10, 14, and 21 days before placing the anthers on callus‐inducing medium. The uninucleate stages gave much higher frequencies of callus induction in both control and treated samples. In general, the more moderate temperature over a 10‐ to 14‐day treatment gave maximum frequency of callus induction. While most of the plants derived from G1 and G2 stage anthers stored in the cold for 2 weeks or less were green, plants from later pollen stages or 21 days of cold storage were predominately albino.

Culture of whole barley spikes stimulates high frequencies of pollen calluses in individual anthers

Whole barley spikes were cultured in agitated liquod medium. In some anthers 70% of all microspores divided abnormally, resulting in similar frequencies of pollen callus production. Macroscopic calluses subsequently developed from 30% of all anthers in certain spikes. These calluses contained mixtures of haploid, diploid and polyploid cells. This may be considered as a particularly suitable method for initiating plant production from the male gametophytes of cereal crops. However the requisite conditions or the large scale production of green plants from these calluses remain to be identified.