Marker assisted backcross breeding to enhance drought tolerance in Kenyan chickpea (Cicer arietinum L.) germplasm

Drought is the number one constraint in chickpea production. In the past, breeding efforts to improve terminal drought tolerance have been hindered by its quantitative genetic basis and poor understanding of the physiological basis of yield in water-limited conditions

Evaluation Of Pigeonpea Pod Borer And Pod Fly Tolerant Lines At Kabete And Kiboko In Kenya

Pigeonpea lines which have shown tolerance to pod borer and pod fly damage at ICRISAT, Patancheru, India, were tested in the field at Kabete and Kiboko, Kenya, and compared with five local checks. There were sprayed and unsprayed plots for each line. Endosulfan 35 E.C. was applied at 0.07% active ingredient (a.i.) starting at flower bud expansion stage, at 50% flowering, early podding, and full podding stages. At crop maturity, all pods from three plants plot-1 were sampled and seed damage by different insect pests determined. The results showed that seeds from all lines were damaged by pod borers and pod sucking bugs. Pod fly incidence was greater at Kabete than at Kiboko, and damage was lower on test lines than on checks. Spraying reduced seed damage from 57.6% to 9.3% and from 59.9% to 4.5% on pod borer lines and pod fly lines, respectively, at Kiboko, and from 19.9% to 5.4% on pod fly lines at Kabete. At Kiboko seed damage in unsprayed pod borer (57.6%) and pod fly (59.9%) lines was similar. Seed damage on pod fly lines at Kiboko (59.9%) was significantly higher than at Kabete (19.9%). Positive significant correlations were observed between seed mass and pod fly damage at Kabete (r = 0.31*) and Kiboko (r = 0.30*). The results indicated that although some lines showed tolerance to pod borer and pod fly damage, they were highly susceptible to pod sucking bugs, suggesting that such tolerance does not hold against other insect groups.Des lign\ue9es de pois d'Angole qui se sont montr\ue9es tol\ue9rantes aux foreurs des gousses et aux mouches des gousses \ue0 l'ICRISAT-Patancheru, en Inde, ont fait l'objet des essais \ue0 Kabete et \ue0 Kiboko au Kenya et ont \ue9t\ue9 mises en comparaison avec cinq t\ue9moins locaux. Pour chaque lign\ue9e, il y a eu des parcelles pulv\ue9ris\ue9es et non pulv\ue9ris\ue9es. On a appliqu\ue9 l'endosulfan 35 E.C. \ue0 0,07% de mati\ue8re active d'abord \ue0 l'\ue9tape d'expansion des bourgeons florales, ensuite \ue0 50% de floraison, au d\ue9but et \ue0 la fin de la formation des gousses. Au stade de maturation, toutes les gousses pr\ue9lev\ue9es sur trois pieds par parcelle ont \ue9t\ue9 mises \ue0 l'\ue9chantillonnage afin de d\ue9terminer les d\ue9g\ue2ts caus\ue9s aux grains par des insectes ravageurs diff\ue9rents. Les r\ue9sultats ont r\ue9v\ue9l\ue9 que les grains de toutes les lign\ue9es ont \ue9t\ue9 atteints par des foreurs des gousses et des punaises suceuses de gousse. L'incidence des mouches des gousses a \ue9t\ue9 plus \ue9lev\ue9e \ue0 Kabete qu'\ue0 Kiboko. Les d\ue9g\ue2ts dus aux mouches des gousses ont \ue9t\ue9 plus faibles sur les lign\ue9es d'essais que sur les t\ue9moins. La pulv\ue9risation a permis de r\ue9duire les d\ue9g\ue2ts aux grains de 57,6% \ue0 9,3% chez des lign\ue9es tol\ue9rantes aux foreurs des gousses et de 59,9% \ue0 4,5% chez des lign\ue9es tol\ue9rantes aux mouches des gousses \ue0 Kiboko. A Kabete, la pulv\ue9risation a r\ue9duit les d\ue9g\ue2ts de 19,9% \ue0 5,4% chez des lign\ue9es tol\ue9rantes aux mouches des gousses. A Kiboko, les d\ue9g\ue2ts aux grains chez des lign\ue9es non pulv\ue9ris\ue9es tol\ue9rantes aux foreurs des gousses (57,6%) et aux mouches des gousses (59,9%) ont \ue9t\ue9 similaires. Les d\ue9g\ue2ts chez des lign\ue9es tol\ue9rantes aux mouches des gousses ont \ue9t\ue9 significativement plus \ue9lev\ue9s \ue0 Kiboko (59,9%) qu'\ue0 Kabete (19,9%). Des correlations significatives positives ont \ue9t\ue9 observ\ue9es entre le poids des grains et les d\ue9g\ue2ts dus aux mouches des gousses \ue0 Kabete (r = 0,31*) et \ue0 Kiboko (r = 0,30*). Les r\ue9sultats ont indiqu\ue9 que certaines lign\ue9es se sont montr\ue9es tol\ue9rantes aux d\ue9g\ue2ts dus aux foreurs des gousses et aux mouches des gousses. Cependant, elles ont \ue9t\ue9 tr\ue8s sensibles aux punaises suceuses de gousse, ce qui laisse sugg\ue9rer que de telle tol\ue9rance ne pourrait pas r\ue9sussir contre d'autres groupes d'insectes

Yield response to phosphorus fertilizer in a wheat - lentil rotation in a mediterranean environment

AbstractThe effect of a single application of phosphorus (P) fertilizer on yields of wheat and a following lentil crop was studied in two-course rotational trials under rainfed conditions in a Mediterranean-type environment. Wheat was grown during the 1984/85 and 1985/86 growing seasons at three sites in north-west Syria, with P applied at rates of 0, 17.5, 35.0 and 52.5 kg ha−1. Lentil (Lens culinaris Med.) was grown during the 1985/86 and 1986/87 seasons at the same sites, following the wheat crops. During the 1985/86 season, no additional P was applied to the lentil crop. During the 1986/87 season, additional P was applied to the lentil crops grown at two of the three sites, in order to compare the residual and direct effects of P fertilizer application. Initial contents of extractable soil P (P-Olsen) were low at all sites: in the range of 2–5 ppm. The response of wheat to direct application of P and of lentil to residual P were described by a modified Mitscherlich equation accounting for the effect of rainfall on potential yield (under rainfed conditions) and on the availability of P to the crop. Under the conditions of the experiments, lentil benefited significantly from P fertilizer applied to the preceding wheat crop. It was concluded that a single application of P to the wheat crop in a wheat-lentil rotation would reduce the cost of lentil production without significantly reducing lentil yields

Response of Pigeonpea Genotypes of Different Maturity Duration to Temperature and Photoperiod in Kenya

Pigeonpea ( Cajanus cajan (L.) Millsp.) is one of the major grain legumes grown in the tropics and subtropics. The crop is grown rainfed in prone drought areas where day length varies from 11 to 14 h and large differences in temperature are experienced, largely due to variations in altitude and latitude. Field studies were conducted with different pigeonpea [Cajanus cajan (L.) Millsp.] in Kenya to determine the effect of photoperiod and temperature on flowering. Variation in temperature was achieved by planting six genotypes at four locations varying in altitude where temperature decreased with increase in altitude and variation in photoperiod was achieved through artificial lighting (about 12.6 hr - natural day length, 14.5 hr and 16.0 hr). The genotypes used in the study were carefully selected to represent different maturity duration (extra-short-, short-, medium- and long maturity duration) and major piegonpea production regions. Equations that describe the rates of development (1/f) were used to determine rates of progress of each genotype towards flowering as influenced by temperature and photoperiod. For photoperiods below 13 hr, rates of progress towards flowering were influenced by temperature in give genotypes (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 and ICEAP 00040). The optimum temperature for rapid flowering were 24.7 °C for the extra-short-duration genotype, 23.1 °C for the shortduration genotye, 23.8 and 22.2 °C for medium-duration genotypes and 18.3 °C for the long-duration genotypes, 22.2 °C for medium-duration genotypoes and 18.3 oC for the long-duration genotypes which indicated that the area of origin had a strong influence on adaptation. The effects of photoperiod on rates of progress towards flowering were investigated only under sub-optimal temperatures. The extra-short-duration genotype (ICPL 90011) was the least responsive to variation in photoperiod, while the two long duration genotypes (ICEAP 00040 and T-7) were to most sensitive to photoperiod variation with flowering rate reduced by 0.001 d-1 per hour increase in day length.Le pois pigeon ( Cajanus cajan (L.) Millsp) est une des principales légumes plantées dans les régions tropicales et subtropicales. La culture est alimentée par les pluies pour sa croissance dans les zones susceptibles de sécheresse, au sein desquelles la durée de la journée varie de 11à 14h et des grandes différences de température sont observées, en majorité dues aux variations d'altitude et de latitude. Des études de terrain étaient conduites avec différents types de pois pigeon [Cajanus cajan (L.) Millsp.] au Kenya en vue de pouvoir déterminer l'effet de la photopériode et de la température sur la floraison. Les variations de température étaient réalisées au moyen de six génotypes plantés dans quatre endroits d'attitude différentes où la température baissait en fonction d'un accroissement en attitude tandis que la variation de photopériode était atteinte par éclairage artificiel (Environ 12,6 hr - longueur de journée naturelle, 14, 5hr et 16, 0hr). Les génotypes utilisés au cours de l'étude étaient attentivement choisis en vue de pouvoir représenter des durées de maturité variables (extra-courte, courte, moyenne et longue) ainsi que les principales régions productrices de pois pigeon. Des équations décrivant le taux de développement (1/f) étaient utilisées dans le but de déterminer le taux de progression de chaque génotype vers la floraison tel qu'influencé par la température et la photopériode. Pour des photopériodes ne dépassant pas 13 hr, ces taux étaient influencés par la température dans des génotypes donnés (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 et ICEAP 00040). La température optimale pour une croissance rapide étaient de 24.7°C pour le génotype à durée extra-courte, 23,1°C pour celui à durée courte, 23,8°C et 22,2°C pour le génotype à durée moyenne et enfin 18,3°C pour celui à longue durée; ce qui montrait que la région d'origine présentait une forte influence sur l'adaptation. Les effets de la photopériode sur le taux de progrès vers la floraison étaient recherchés seulement sous températures sub-optimales. Le génotype à durée extra-courte (ICPL 90011) était le plus réceptif quant aux variations de photopériode, pendant que les 2 génotypes à durée longue (ICEAP 00040 et T-T) étaient les plus réceptifs à la variation de la photopériode, avec des taux de floraison réduits de 0.0001 d-1 par heure d'augmentation en longueur de journé

Pigeonpea breeding in eastern and southern Africa: challenges and opportunities

Pigeonpea (Cajanus cajan [L.] Millspaugh) is an important multipurpose grain legume crop primarily grown in tropical and subtropical areas of Asia, Africa and Latin America. In Africa, the crop is grown for several purposes including food security, income generation, livestock feed and in agroforestry. Production in Eastern and Southern Africa (ESA) is however faced with many challenges including limited use of high-yielding cultivars, diseases and pests, drought, under-investment in research and lack of scientific expertise. The aim of this review is to highlight the challenges facing pigeonpea breeding research in ESA and the existing opportunities for improving the overall pigeonpea subsector in the region. We discuss the potential of the recently available pigeonpea genomic resources for accelerated molecular breeding, the prospects for conventional breeding and commercial hybrid pigeonpea, and the relevant seed policies, among others, which are viewed as opportunities to enhance pigeonpea productivity

Marker assisted backcross breeding to enhance drought tolerance in Kenyan chickpea (Cicer arietinum L.) germplasm

Drought is the number one constraint in chickpea production. In the past, breeding efforts to improve terminal drought tolerance have been hindered by its quantitative genetic basis and poor understanding of the physiological basis of yield in water-limited conditions

Chickpea breeding and development efforts in Eastern and Southern Africa: Achievements and opportunities

In Eastern and Southern Africa(ESA), chickpea is grown on about 493,000 ha. Ethiopia and Tanzania are the major chickpea growing countries by occupying 73% of total ESA area, and minor producing countries are Malawi, Kenya, Eritrea, Sudan and Uganda. Chickpea provides a unique oppourtunity to grow in post-rainy season under residual moisture conditions. Ethiopia is the major chickpea producer and exporter in ESA and during last one decade production(119%) and productivity(78%) have increased substantially. Ethiopia and Tanzania export a sizable quantities of chickpea and earning about 46.6 million $ annually. Chickpea improvement in ESA over the years resulted in release of 40 high yielding varieties with desirable agronomic and quality traits. The major breeding priorities in ESA were high grain yield, resistance to Fusarium wilt, collar rot, dry root rot and ascochyta blight;tolerance to Helicoverpa pod borer, terminal drought and grain quality traits. The current productivity levels in Ethiopia is about 1730 kg/ha and but in all other ESA countries productivity levels are still below 1000 kg/ha. The productivity gains in Ethiopia, providing an opportunity for cross learning among neighbouring countries. The new varieties and breeding populations developed by ICRISAT using conventional and molecular breeding approaches have been evaluated in ESA and their adaptability and adoption rates are very high. However, a huge untapped yield potential exists in the currently released as well as pipe line varieties. Better integration of available genomic and genetic resources in breeding, effective seed production and delivery, integrated crop management, wider stakeholder participation will provide an oppourtunity to futher enhance on-farm yields

Pigeonpea breeding in Eastern and Southern Africa: achievements and future prospects

Pigeonpea is no more an orphan crop in Eastern and southern Africa(ESA), with its multiple benefits to cropping systems, smallholder farmers, consumers and traders. pigeonpea has huge regional and international export potential and india alone imports 506,000 t annually. ESA countries export about 200,000 t of grain per year that worth $ 180 million. During the last two decades, area and production in ESA increased dramatically by 135% and 125%, respectively. Tanzania, Malawi, Mozambique, Kenya and Uganda are the major pigeonpea producers. Tanzania and Malawi are showing the path to success in terms of productivity and production gains that guide other countries to follow. Pigeonpea improvement in ESA started in 1992 and since then 27 high yielding varieties were released and adopted them widely. The major breeding priorities were high grain yield, inter-cropping compatibility, photo-period insensitivity, grain quality, resistance/tolerance to Fusarium wilt, Helicoverpa pod borer and resilience to climate change. ESA has unique genetic diversity and its use in genetic enhancement has paid rich dividends. Tremendous yield gains have been recoreded with the use of new varieties, integated crop management, effective seed systems and sustained market demand. However, a huge gap still exists between realizable and actual yields with present technologies. ICRISAT-Patancheru is utilizing hybrid pigeonpea technology, genomic and genetic resources most effectively. Efforts are being made to use them in ESA breeding program to further elevate yield potentials in the region. A region specific strategy being outlined to bridge the gaps between actual, realized and potential yields using conventional and modern breeding by involving all the stakeholders