Micronutrient deficiencies are common in locales where people must rely upon sorghum as their staple diet. Sorghum grain is seriously deficient in provitamin A (β-carotene) and in the bioavailability of iron and zinc. Biofortification is a process to improve crops for one or more micronutrient deficiencies. We have developed sorghum with increased β-carotene accumulation that will alleviate vitamin A deficiency among people who rely on sorghum as their dietary staple. However, subsequent β-carotene instability during storage negatively affects the full utilization of this essential micronutrient. We determined that oxidation is the main factor causing β-carotene degradation under ambient conditions. We further demonstrated that coexpression of homogentisate geranylgeranyl transferase (HGGT), stacked with carotenoid biosynthesis genes, can mitigate β-carotene oxidative degradation, resulting in increased β-carotene accumulation and stability. A kinetic study of β-carotene degradation showed that the half-life of β-carotene is extended from less than 4 wk to 10 wk on average with HGGT coexpression.β-carotene accumulation | β-carotene stability | vitamin E | HGGT | biofortified sorghum T he importance of vitamin A for human health has been widely addressed (1-6). A 2009 Global Report (7) summarized vitamin A as being "vital for survival and sight; to boost the immune system, vitamin A is a critical micronutrient for survival and physical health of children exposed to disease." In Africa, malnutrition is a serious challenge, but micronutrient deficiency also plays a dominant role in the overall food security of that continent. Based on this global report, the five countries having the highest proportions of preschool age children with vitamin A deficiency were all located in Africa: 95.6% in Sao Tome and Principe, 84.4% in Kenya, 75.8% in Ghana, 74.8% in Sierra Leone, and 68.8% in Mozambique. Sorghum (Sorghum bicolor L.) is one of the most important staple foods for an estimated 500 million people, primarily those living in arid and semiarid areas. In Africa, it is the second most important cereal; about 300 million people rely on it as their daily staple food. Although sorghum is gluten-free and could be an attractive replacement for wheat-allergy sufferers, it is considered a nutrient-poor crop (8, 9) with very low amounts of β-carotene (10). The improvement of micronutrients in food crops has attracted considerable attention, and significant advances have been made in a range of major crops (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). Nutritional improvement in sorghum was undertaken a decade ago (23, 24); however, progress has lagged behind the progress in other crops. One reason was the recalcitrance of sorghum to genetic modification via transformation. Recent improvements in sorghum transformation have largely overcome this barrier and offer an alternative approach to genetic improvements in sorghum (25).One of our objectives is to develop sorghum lines with enhanced and stabilized provitamin A (β-car...

Break the culture of dependency: Africa is forced to import at least 25 per cent of its grain. GUY MANSFIELD / PANOS PICTURES

Banana (Musa spp.) is one of the most important food and cash crops in Kenya. However, most of the cultivars grown particulary the local ones are low yielders and are thus not very suitable for commercial production. To address this constraint, a study was conducted at Kenya Agricultural Research Institute, Thika to evaluate introduced improved cultivars for agronomic and yield characteristics. The study involved six FHIA and four Cavendish type of bananas obtained from Bioversity International. Different growth and yield parameters were collected for the first, second and third crop cycles. Cultivar SH3436-9 took the longest time to reach the shooting stage, while SH3640 took the shortest time. FHIA 25 took the longest time from shooting stage to maturity, while FHIA 23 took the shortest time. FHIA 25 had the highest bunch weight in the first and third crop cycles, while FHIA 17 had the highest weight in the second crop cycle. Overall, GCTCV-119 produced the smallest bunch. For finger length, FHIA 21 and FHIA 25 led in the first and second crop cycle, respectively. Cultivars FHIA 17, FHIA 18 and FHIA 25 were identified as the most promising for commercial production, but further evaluation is required in other zones to establish whether this impressive performances would be sustained.Key Words: Bunch weight, FHIA banana, Musa spp. RÉSUMÉLa banane (Musa spp). Est l'une des nourriture les plus importantes et de production des revenus au Kenya. Cependant, la plupart des cultivars dévéloppées particulièrement local est moins productitif et est moins convenable pour la production commerciale. Pour adresser cette contrainte, une étude a été dirigée à Institut de Recherche Agricole au Kenya, Thika pour évaluer des cultivars améliorés introduits pour les caractéristiques agronomique et de rendement. L'étude a impliqué six FHIA et quatre types de bananes Cavendish obtenues d'INIBAP. Les différentes croissances et nivequx de rendement ont été recueillis pour les premiers deuxièmes et troisièmes cycles de récolte. Le cultivar SH3436-9 a pris le temps le plus long pour atteindre l'étape de l'emergence de rejetons, pendant que SH3640 a pris le temps le plus court. FHIA 25 ont pris le temps le plus long concernant l'emergence de rejetons d'étape à l'échéance, pendant que FHIA 23 a pris le temps le plus court. FHIA 25 a eu le regime de plus haut poids dans le premier et troisième cycle de récolte, pendant que FHIA 17 a eu le poids le plus haut dans le deuxième cycle de récolte. En général, GCTCV-119 a produit le plus petit regime. Pour la longueur de doigts des bananes, FHIA 21 et FHIA 25 ont respectivement mené dans le premier et deuxième cycle de récolte. Les cultivars FHIA 17, FHIA 18 et FHIA 25 ont été identifiés comme le plus promettant pour la production commerciale, mais l'évaluation plus poussée est recmmandée dans les autres zones pour établir si ces performances impressionnantes seraient soutenues.Mots Clés: Le poids de paquet, la banane de FHIA, Musa spp. J. NJUGUNA et al. 36

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