The first haploid angiosperm, a dwarf form of cotton with half the normal chromosome complement, was discovered in 1920, and in the ninety years since then such plants have been identified in many other species. They can occur either spontaneously or can be induced by modified pollination methods in vivo, or by in vitro culture of immature male or female gametophytes. Haploids represent an immediate, one-stage route to homozygous diploids and thence to F(1) hybrid production. The commercial exploitation of heterosis in such F(1) hybrids leads to the development of hybrid seed companies and subsequently to the GM revolution in agriculture. This review describes the range of techniques available for the isolation or induction of haploids and discusses their value in a range of areas, from fundamental research on mutant isolation and transformation, through to applied aspects of quantitative genetics and plant breeding. It will also focus on how molecular methods have been used recently to explore some of the underlying aspects of this fascinating developmental phenomenon.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-7652.2009.00498.x

Haploids in flowering plants: origins and exploitation.

Role of biotechnological interventions in the improvement of castor (Ricinus communis L.) and Jatropha curcas L.

The prospect of biofuels as a transport alternative fuel in Australia is reviewed and discussed in this paper. The Australian transport sector is the second largest energy consuming sector which consumes about 24% of total energy consumption. A part of this energy demand can be met by ecofriendly biofuels. A wide array of different biofuels feedstocks including Australian native species, their distributions, oil content, traditional uses are reviewed and listed in the descending order of their oil content. The world biofuel scenario as well as the 20 largest biofuel production countries and their mandates on biofuels blending with petroleum diesel are presented. Australia’s biofuel production, consumption, production facilities and future investment projects are also reviewed and discussed. The study developed a biofuel supply chain for Australia and found that the second generation biofuels have better prospects as a future alternative transport fuel in Australia. These biofuel feedstocks are readily available and can overcome the shortcomings of the first generation biofuels, such as socio-economic, environmental and food versus land use challenges. Although some research is in progress, further study is needed on the process development of second generation biofuel production at commercial scale in Australia and abroad.

Prospect of biofuels as an alternative transport fuel in Australia.

Medicinal plants are a major source of raw material for the traditional system like Ayurveda, Siddha & Unani. Even the modern system of medicine has more than 25 percent of drugs in use, which are either plant based or plant derived. Although several tree posses various medicinal properties, it has been ignored by indigenous & modern system of medicine. Among them Azadirachta indica & Melia azedarach belonging to family Meliaceae play a vital role in day to day usage of different indigenous communities due to its sacred and medicinal value. Recently there has been an upsurge of interest in the therapeutic potential of medicinal plants as antioxidants. In the course of finding potential antioxidant from plant source, two medicinal tree species belonging to family Meliaceae has been selected. Leaves were dried and extracted with different solvent systems namely water, ethanol & methanol. Antioxidant activity using DPPH radical scavenging assay of six extracts from two genus of the family Meliaceae is reported & a comparison of the free radical scavenging ability of the extracts is emphasized. The result of the present study showed that the extract of Melia azedarach., which contains highest amount of phenolic compounds exhibited the greatest anti-oxidant activity in comparison to Azadirachta indica. The high scavenging property of may be due to hydroxyl groups existing in the phenolic compounds chemical structure that can provide the necessary components as a radical scavenger. (Nature and Science 2010; 8(4):22-28). (ISSN: 1545-0740).

/pdf/in-vitro-antioxidative-acitivity-of-azadirachta-indica-and-5tlg14ptst.pdf

In vitro antioxidative acitivity of Azadirachta indica and Melia azedarach Leaves by DPPH scavenging assay

In order to have standardized formulations, the chemical constituents from plants and their parts are required to be uniform both qualitatively and quantitatively. Furthermore, an ever increasing demand of uniform medicinal plants based medicines warrants their mass cloning through plant tissue culture strategy. A good number of medicinal plants have been reported to regenerate in vitro from their various parts, but a critical evaluation of such reports reveals that only a few complete medicinal plants have been regenerated and still fewer have actually been grown in soil, while their micropropagation on a mass scale has rarely been achieved, particularly in those medicinal plants where conventional propagation is inadequate, like, the mass clonal propagation of Dioscorea floribunda leading to its successful field trials. Such facts make it imperative to document the factual position of micropropagation of medicinal plants bringing out the advancements made along with the short falls, in this important area. The present review deals with the futuristic view on the said subject restricted to higher plants.

http://nopr.niscair.res.in/bitstream/123456789/5689/1/IJEB%2045%2811%29%20937-948.pdf

Cloning of medicinal plants through tissue culture--a review.

Androgenic haploids of the neem tree (Azadirachta indica A. Juss.) were produced by anther culture at the early- to late-uninucleate stage of pollen. Haploid formation occurred via callusing. The best medium for inducing callusing in the anther cultures was Murashige and Skoog's basal medium (MS) (9% sucrose) supplemented with 1 μM 2,4-D, 1 μM NAA and 5 μM BAP, while anther callus multiplied best on MS medium supplemented with 1 μM 2,4-D and 10 μM Kn. These calli differentiated shoots when transferred to a medium containing BAP; 5 μM BAP was optimum for young calli (75% cultures differentiated shoots), but older calli showed the best regeneration with 7.5 μM BAP. Shoots elongated at a lower concentration of BAP—0.5 μM. These shoots were multiplied by forced axillary branching and rooted in vitro. The plants were subsequently established in soil. Of the plants that regenerated from anther callus 60% were haploid, 20% were diploid and 20% were aneuploid.

/pdf/production-of-haploids-of-neem-azadirachta-indica-a-juss-by-37yxirqcue.pdf

Production of haploids of neem (Azadirachta indica A. Juss.) by anther culture

https://www.iitg.ac.in/rakhi_chaturvedi/pdf/books/j29.pdf

In vitro clonal propagation of an adult tree of neem (Azadirachta indica A. Juss.) by forced axillary branching

http://www.iitg.ac.in/rakhi_chaturvedi/pdf/books/j31.pdf

An efficient protocol for the production of triploid plants from endosperm callus of neem, Azadirachta indica A. Juss.

Immature zygotic embryo cultures of neem yielded highly regenerative cultures, with the response varying with the embryo stage at culture Early dicotyledonous stage embryos were the most responsive followed by torpedo stage embryos The embryo cultures differentiated three types of regenerants: somatic embryos (SEs), shoot buds and neomorphs SEs exhibited morphological abnormalities such as pluricotyledony, fusion of cotyledons and absence of cotyledons Although these SEs showed secondary embryogenesis, the occurrence of normal dicotyledonous embryos was extremely rare On MS basal medium 3% of SEs developed a long tap root but a plumular shoot did not appear However, it was possible to regenerate plantlets from immature zygotic embryo cultures of neem via neomorph formation and adventitious shoot bud formation The transplantation survival of these plants was more than 80%

/pdf/in-vitro-morphogenesis-in-zygotic-embryo-cultures-of-neem-521bcb7pmi.pdf

In vitro morphogenesis in zygotic embryo cultures of neem (Azadirachta indica A. Juss.).

Production of haploid plants has been restricted to only a few ornamental species. In this paper an efficient anther culture protocol has been devised for production of haploid plants of Phlox drummondii, a garden ornamental. Anthers with microspores at early- to late-uninucleate stages were inoculated on MS (Murashige and Skoog, Physiol Plant 15:473–479, 1962) basal medium containing 9% sucrose, 10 μM 2,4-D + 5 μM BA in the dark for callus induction. The callus (~2 mm) was transferred to MS medium containing 3% sucrose + 10 μM BA + 5 μM NAA under a 16 h photoperiod for multiplication. Anther-derived callus showed the greatest shoot differentiation (60% with greater than 3 shoots per culture) at 13 weeks after culture initiation when maintained on MS medium supplemented with 3% sucrose and cytokinin (7.5 μM BA). At 68 weeks, only 4.6% of cultures differentiated with less than one shoot per callus. Anther-derived shoots rooted readily on MS medium containing 7.5 μM IAA. Of 60 plants that regenerated from anther callus, 50% were haploid, 30% diploid, and 20% aneuploid. Developed protocol could be useful for the haploid induction of outcrossing ornamental plants for production of their homozygous double haploids.

M. K. Razdan

Papers

Production of haploids of neem (Azadirachta indica A. Juss.) by anther culture

In vitro clonal propagation of an adult tree of neem (Azadirachta indica A. Juss.) by forced axillary branching

An efficient protocol for the production of triploid plants from endosperm callus of neem, Azadirachta indica A. Juss.

In vitro morphogenesis in zygotic embryo cultures of neem (Azadirachta indica A. Juss.).

Efficient protocol for in vitro production of androgenic haploids of Phlox drummondii