Shri Mohan Jain

In vitro hermaphrodism induction in date palm female flower

This study explores and reports on the gain brought to the morphogenetic aptitude of female date palm inflorescences through in vitro hermaphrodism induction. It investigates the main factors involved in the process of sex modification through hormonal induction, such as the floral developmental stage and hormone combination and concentration. It demonstrates that the vestigial stamens (staminodes) of female date palm flowers display a new and high capacity to proliferate under particular in vitro conditions, without blocking carpel’s development, leading to morphologically typical hermaphrodite flowers. This de novo activation of repressed stamens was found to occur rapidly. The isolated pollen mother cells appear in the obtained anther’s locules and undergo an ordinary microsporogenesis process. The data show that hermaphrodism induction depended heavily on both the growth regulators applied and the flower’s developmental stage. They also confirm the early theory that suggests that dioecious plants come from a hermaphrodite ancestor. Such hermaphrodism control can provide new prospects and opportunities for the investigation of the in vitro self-fertilization process. It can also be useful in improving the understanding of the genetic mechanism involved in sex organ development in date palm.

Date Palm Genetic Resources and Utilization

Successful future development of date palm depends largely on evaluating, utilizing, and conserving genetic resources; assessing the value of present and potential cultivars; promoting the best cultivation, processing, and marketing practices; and broadening the number of fruit and tree products. The date palm was domesticated at the dawn of agriculture, new technologies were adopted for its cultivation, the palm was dispersed widely by humans and it has become a major world tree crop with the introduction of modern plantations. France, the USA, and international organizations have contributed to date palm development and more recently domestic programs in the larger producing countries. Creating a new international date palm organization to bring together research and development efforts and to serve as a resource center would be benefi cial. Date palm cultivation has a long history across North Africa; Algeria, Egypt, Libya, Morocco, and Tunisia are major world fruit producers. Traditional date cultivation in oases is common, with recent and ongoing expansion of organized plantations. North Africa has potential for increased production given its proximity to existing European markets, but serious pest and disease problems must be overcome. Domestic and international research and development support and familiarity with the crop are assets. In the Sahel and Southern Africa, dates are minor crops but with potential for development to meet domestic demand. Advantages include favorable climatic and soil conditions and lesser pest and disease problems. Similar advantages exist in the Americas. Because they are not included in country chapters, summary accounts of date cultivation in Benin, Kenya, Mexico, and Namibia are provided. D. V. Johnson (*) Consultant , Cincinnati , OH , USA e-mail: djohn37@aol.com J. M. Al-Khayri Department of Agricultural Biotechnology , King Faisal University , Al-Hassa 31982 , Saudi Arabia e-mail: jkhayri@kfu.edu.sa S. M. Jain Department of Agricultural Sciences , University of Helsinki , PL-27 , Helsinki 00014 , Finland e-mail: mohan.jain@helsinki.fi

TILLING, high-resolution melting (HRM), and next-generation sequencing (NGS) techniques in plant mutation breeding

Induced mutations have been used effectively for plant improvement. Physical and chemical mutagens induce a high frequency of genome variation. Recently, developed screening methods have allowed the detection of single nucleotide polymorphisms (SNPs) and the identification of traits that are difficult to identify at the molecular level by conventional breeding. With the assistance of reverse genetic techniques, sequence variation information can be linked to traits to investigate gene function. Targeting induced local lesions in genomes (TILLING) is a high-throughput technique to identify single nucleotide mutations in a specific region of a gene of interest with a powerful detection method resulted from chemical-induced mutagenesis. The main advantage of TILLING as a reverse genetics strategy is that it can be applied to any species, regardless of genome size and ploidy level. However, TILLING requires laborious and time-consuming steps, and a lack of complete genome sequence information for many crop species has slowed the development of suitable TILLING targets. Another method, high-resolution melting (HRM), which has assisted TILLING in mutation detection, is faster, simpler and less expensive with non-enzymatic screening system. Currently, the sequencing of crop genomes has completely changed our vision and interpretation of genome organization and evolution. Impressive progress in next-generation sequencing (NGS) technologies has paved the way for the detection and exploitation of genetic variation in a given DNA or RNA molecule. This review discusses the applications of TILLING in combination with HRM and NGS technologies for screening of induced mutations and discovering SNPs in mutation breeding programs.

Advances in Plant Breeding Strategies: Breeding, Biotechnology and Molecular Tools

The domestication of plants, as a bio-cultural process, is a continuous phenomenon intrinsically associated with the use of plants. Traditional and scientifi c knowledge constitute the basis of the various uses of plants from in situ harvesting to complete domestication of crops. One of the most important challenges of our time is to achieve the conservation and sustainable use of plant genetic resources of landraces, species in the process of domestication and species used in situ. The in situ conservation of agricultural biodiversity is a basic element for the development of more sustainable agroecosystems, the adaptation to climate change, the conservation of ecosystem services and to ensure local food security—a conception that is strongly linked to the local development and the protection of cultural and biological diversity. Through case studies from the Pampa Biome we will discuss the valorization of plant genetic resources through new domestication, the promotion of the use of scientifi cally developed best management practices for in situ conservation, the widening of the germplasm base for breeding programs, plant breeding for stress tolerance, the development of participatory plant breeding programs and the development of high quality products.

Protocol for Inducing Flower Color Somaclonal Variation in Torenia ( Torenia fournieri Lind.)

White or light purple flower color Torenia (Torenia fournieri Lind.) varieties were successfully developed from the parental variety having violet flowers. This was accomplished by reducing Fe micronutrient in the culture media for the induction of in vitro flowering. The flower induction was highest in modified Murashige and Skoog (MS) medium containing ½ strength of macroelements, microelements, organic additives, and full Fe (M1) when compared to MS medium containing ½ strength of macronutrients, micronutrients, full Fe, and full organic additives (M2). The flower color was stable in two new Torenia varieties through three generations ex vitro. The results showed a wide range of somaclonal variation in flower colors; early flowering occurred in MS medium containing ½ strength of macroelements, microelements, Fe, and full strength of organic additives (M3). The selection of desirable somaclones and their micropropagation in subsequent generations led to the development of new and stable Torenia lines.

Introduction: Date Production Status and Prospects in Asia and Europe

Successful future development of date palm depends largely on evaluating, utilizing, and conserving genetic resources; assessing the value of present and potential cultivars; promoting the best cultivation, processing, and marketing practices; and broadening the number of fruit and tree products. The date palm was domesticated at the dawn of agriculture, new technologies were adopted for its cultivation, the palm was dispersed widely by humans and it has become a major world tree crop with the introduction of modern plantations. France, the USA, and international organizations have contributed to date palm development and more recently domestic programs in the larger producing countries. Creating a new international date palm organization to bring together research and development efforts and to serve as a resource center would be beneficial. Date cultivation originated in Iraq and that country has always been a major producer; Iran, Saudi Arabia, Pakistan, Oman, and the United Arab Emirates also are all primary world producers. These countries present a mixed pattern of old and new date cultivation which receive federal government support for research and development. In recent decades, cultivation in the Arabian Peninsula has expanded significantly with new plantations using tissue-cultured plants. Date production in Pakistan and India comes mostly from seedling date palms under traditional cultivation. Modern date cultivation is being established to meet the large domestic demand. Israel’s date production is unique coming entirely from modern plantations. Spain’s very small date production from seedling dates is a novelty and likely to remain so. Because they are not included in country chapters, summary accounts of date cultivation in Jordan and the United Arab Emirates are included.

Advances in Date Palm (Phoenix dactylifera L.) Breeding

Date palm is one of the oldest cultivated plants, grown in the arid and semiarid regions of the world. The date fruit serves as a vital worldwide component of the human diet and a staple food for millions of people. Unfortunately, various abiotic and biotic stresses along with agronomic constraints are hindering date productivity. Those date cultivars adapted to stress conditions have low fruit production. Conventional breeding, depending on crosses and backcrosses, is a time-consuming process. The applied research carried out on date palm is limited, still there is enormous potential to improve date palm breeding methods. Advanced biotechnology creates unparalleled opportunities to develop new varieties with quality fruit, increased fruit yield and resistance to pests and pathogens. It also minimizes the application of potentially-harmful fungicides and pesticides and increases crop productivity. This chapter provides current and innovative information about date palm progress in terms of distribution, production, marketing strategy, current achievements, limitations and challenges facing date palm breeding. It also focuses on recent advances in tissue culture, genetic transformation and molecular breeding to improve the productivity and quality of the date.

First reported case of spontaneous hermaphrodism in female date palm (Phoenix dactylifera L.), cv ‘Alligue’

ABSTRACT The date palm (Phoenix dactylifera L.) is dioecious with male flowers deficient in functional gynoecium and female flowers deficient in functional androecium borne on separate palms. The presence of male and female flowers on the same plant, a phenomenon known as monoecy, is unusual in male date palms. This study reports for the first time on hermaphrodite (bisexual) flowers borne by two female date palms, ‘Alligue’, that were found growing in an open field in Degache, southern Tunisia. The observations on these two female palms were compared with hermaphrodite male date palms growing in the same location. Hermaphrodite female date palm inflorescence branches bear female flowers predominantly near their base, in contrast to the hermaphrodite flowers that are found primarily toward their upper part. The position of the hermaphrodite flowers in hermaphrodite male date palms is reversed: inflorescence branches bear male flowers toward the upper part while the hermaphrodite flowers are found at the base. Histological examination of female hermaphrodite flowers revealed that they had three carpels and 1–6 stamens. Hermaphrodite flowers on male plants were usually also composed of three carpels of variable size, and six stamens. Hermaphrodite flowers on both female and male palm trees turn generally into parthenocarpic fruits. The present data support the theory that dioecious plants are derived from a common hermaphrodite ancestor. Floral hermaphroditism in date palm should be investigated in relation to the in planta self-fertilization process to identify sex markers and genes that control sex organ development.