Using Lens lamottei to transfer anthracnose resistance to lentil varieties

Non-Peer ReviewedAnthracnose is a serious fungal disease of lentil that can cause severe yield loss. It is now widespread in Saskatchewan and can be devastating in years with warm wet weather. Producers are limited to controlling this disease by crop rotation, foliar spray or development of varieties with resistance to anthracnose. Pathology research shows that we have two major strains of lentil anthracnose. Varieties like CDC Robin have resistance to one of the strains, but after exhaustive screening of cultivated lentil germplasm, no resistance was found to the second strain of anthracnose. One of the newly discovered wild species of lentil, Lens lamottei, has recently been discovered to have resistance to a combination of both strains of anthracnose when grown under field conditions in an inoculated disease nursery. The objective of this project is to determine if L. lamottei can be by crossed with L. culinaris in order to transfer anthracnose resistance into lentil varieties

Genetic improvement of chickpea for western Canada

Non-Peer ReviewedThe chickpea crop has experienced a roller-coaster ride over the past decade in western Canada. Production rose rapidly in the late 1990’s, followed by dramatic declines in the past two years. Instability can be attributed to many factors including commodity prices, erratic weather patterns, Ascochyta blight and late maturity. This paper summarizes current research on genetic improvement of chickpea at the University of Saskatchewan, with particular emphasis on efforts to improve Ascochyta blight resistance and to develop varieties with earlier maturity. Under ‘average’ weather conditions, chickpea remains an excellent nitrogen-fixing crop for the Brown and Dark Brown soil zones

Revisiting strategies for breeding anthracnose resistance in lentil: the case with wild species

Non-Peer ReviewedBreeders at the Crop Development Centre (CDC) have up to now only used germplasm resources available in the cultivated lentil to develop new varieties with resistance to diseases. Based on recent studies, the available cultivated germplasm does not offer sufficient genetic variation for resistance to anthracnose and ascochyta diseases. Lentil crop is attacked by two major diseases (anthracnose and ascochyta) that can cause 100% loss in the worst scenarios. Since anthracnose is only a major lentil disease in North America, no work has been done to improve resistance to this disease elsewhere. Wild species of many crops are known to carry many disease resistance genes lacking in the cultivated crop. We began the search for anthracnose resistance in the six wild species of lentil (world collection), of which two can be easily crossed with the cultivated type. Two strains of anthracnose (race 1 and race 2) with varying degrees of virulence were reported. The 2002 field data suggested that some of the Lens ervoides and Lens lamottei accessions exhibited no lesions at all when exposed to the combination of the two anthracnose strains. The cultivated types that show resistance to the less virulent strain were severely affected by anthracnose. In the greenhouse study the wild species were inoculated with the two strains separately and results indicate that no accession is immune to the more virulent type. However, some of the L. ervoides and L. lamottei accessions had good resistance compared to their cultivated counterparts. As a long term strategy, the lentil breeding program at CDC, University of Saskatchewan has a goal of fully utilizing the available resistance sources. However, these two species cannot be easily crossed with the cultivated types using the conventional/manual crossing techniques. A tissue culture procedure involving embryo rescue is used to facilitate crossing. We have been able to successfully rescue some embryos from crosses with Lens ervoides. The hybrid plants produce some fertile seeds which will be evaluated for resistance to both anthracnose and ascochyta. The selected resistant lines will then be backcrossed to the adopted backgrounds in order to deploy resistance genes

Embryo rescue and plant regeneration in vitro of selfed chickpea (Cicer arietinum L.) and its wild annual relatives

The main constraint to the transfer of desired traits into cultivated chickpea from wild Cicer relatives is the presence of post-zygotic barriers which result in abortion of the immature embryo following interspecific hybridisation. Rescue of hybrid embryos in vitro and regeneration of hybrid plantlets could allow chickpea breeders to transfer desirable traits from wild relatives of chickpea. The development of embryo rescue techniques using selfed chickpea and selfed wild relatives is being used as a first step to protocols for wide hybrids. Optical microscopy studies of embryogenesis, in both selfs and hybrids, identified deleterious changes in the fertilised hybrid seed as early as 2–4 days after pollination in some crosses. These observations suggest that the appropriate time to rescue chickpea × C. bijugum hybrids is at the early globular stage of embryogenesis (2–7 days old), which requires the development of a complex tissue culture medium. In contrast hybrids between chickpea × C. pinnatifidum abort later (up to 15–20 days old) at the heart-shaped or torpedo stages, and are easier to rescue in vitro. Genotype also plays a significant role in the ability of immature selfed ovules to germinate in vitro. In this paper we report on the optimisation of␣protocols for rescueing immature embryos using selfed chickpea and its wild relatives in ovule, and subsequently to regenerate plantlets

Androgenesis and doubled-haploid production in food legumes

International audienc

Antigibberellin-induced reduction of internode length favors in vitro flowering and seed-set in different pea genotypes

International audienceIn vitro flowering protocols were developed for a limited number of early flowering pea (Pisum sativum L.) cultivars. This work was undertaken to understand the mechanisms regulating in vitro flowering and seed-set across a range of pea genotypes. Its final goal is to accelerate the generation cycle for faster breeding novel genotypes. We studied the effects of in vivo and in vitro applications of the antigibberellin Flurprimidol together with radiation of different spectral compositions on intact plants, plants with the meristem removed, or excised shoot tip explants. Based on our results, we present a simple and reliable system to reduce generation time in vitro across a range of pea genotypes, including mid and late flowering types. With this protocol, more than five generations per year can be obtained with mid to late flowering genotypes and over six generations per year for early to mid flowering genotypes

Endogenous hormone profiles during early seed development of C. arietinum and C. anatolicum

Cicer anatolicum, a perennial species, has ascochyta blight resistance superior to that found in the cultivated chickpea. However, hybridization barriers during early stages of embryo development curtail access to this trait. Since hormones play an essential role in early embryo development, we have determined the hormone profiles of 4-, 8-, and 12-day old seeds from a Canadian chickpea (Cicer arietinum L.) cv. CDC Xena, from Indian cvs. Swetha and Bharati, and from a perennial accession of C. anatolicum (PI 383626). Indole-3-acetic acid content peaked on day 4 in CDC Xena, on day 8 in both Indian cultivars but only on day 12 in C. anatolicum. The cytokinins, isopentenyladenosine (iPA) and trans zeatin riboside (tZR) were predominant in CDC Xena and Swetha seeds on day 4, whereas cis zeatin riboside was the major component in Bharati. In C. anatolicum, iPA maxed out on day 4 and tZR on day 12. The bioactive gibberellin GA1 spiked on day 4 in CDC Xena and Bharati, on day 8 in Swetha but only on day 12 in C. anatolicum. Eight-day old seeds had the highest abscisic acid content in the cultivars but spiked on day 12 in the perennial species. The hormone profiles of the perennial species showed delayed spikes in all four hormone groups indicating that there is a mismatch in the hormone requirements of the different embryos. Improving synchronization of early seed hormone profiles of cultivated and perennial chickpea should improve interspecific hybrid production.Peer reviewed: YesNRC publication: Ye