Physio-biochemical Responses of In Vitro Cooking Banana Musa paradisiaca cv Lang towards Pseudo Induced Drought Stress by Polyethylene Glycol (PEG)

Musa paradisiaca cv Lang belongs to cooking banana group, and it has high potential to be used in banana chips production. Like other cultivars, M. paradisiaca cv Lang is susceptible towards water shortage, therefore affecting banana growth and productivity. In this study, to mimic the drought condition, pseudo-drought stress was given to in vitro Lang banana seedlings by adding polyethylene glycol (PEG). Overall, decrement of roots length and chlorophyll (Chl) content was displayed by the seedlings exposed to 1%, 2%, 3%, 4%, and 5% (w/v) of PEG after three weeks of exposure. The proline content, total soluble protein content, and antioxidant capacity in leaf and roots, however, countered differently towards different levels of drought. Proline content showed the highest in leaf of 2% (w/v) PEG-treated seedling (12.66±0.38 µmoles/g) while the total soluble protein content showed the highest in roots of 5% (w/v) of PEG-treated seedling (30.65±1.07 mg/g FW). Antioxidant capacity of stressed seedlings revealed the catalase (CAT), guaiacol peroxidase (POD), and ascorbate peroxidase (APX) activities were the highest in the leaf of 1% (w/v) (10.69±5.06 µmol/min/mg), 4% (w/v), (0.079±0.03 µmol/min/mg), and 5% (w/v) (9.11±8.47 µmol/min/mg) of PEG- treated seedlings, respectively. Meanwhile, the highest CAT, POD, and APX activities in the roots were determined in 3% (w/v) (0.49±0.04 µmol/min/mg), 2% (w/v) (0.03±0.02 µmol/min/mg), and 3% (w/v) (16.69±0.5 µmol/min/mg) of PEG-treated seedlings, respectively. These data show that PEG can be a priming agent to induce defense system at seedling stage of banana, which could enhance their survivability during ex vitro acclimatization.

Diversity of nematodes on banana (Musa spp.) in Kenya linked to altitude and with a focus on the pathogenicity of Pratylenchus goodeyi

Summary Bananas (Musa spp.) are considered the most important fruit crop in Kenya, grown mostly by smallholder farmers. However, in the past two decades production has declined and has largely been attributed to plant pathogens, including plant-parasitic nematodes. To assess the understanding and awareness that banana farmers have of nematodes, a survey was conducted. The incidence, abundance and distribution of nematodes in relation to altitude were determined for different banana types on 180 farms and the pathogenicity of Pratylenchus goodeyi, originating from three different altitudinal locations, was compared on two banana cultivars. Just 2.3% of farmers were aware of nematode damage and symptoms, none of whom applied any management measures. The highest abundance of nematodes was recorded at an altitude range of 1601-2000 m a.s.l., with Pratylenchus, Meloidogyne and Helicotylenchus being the predominant genera. Across all altitudinal locations, cooking banana had higher densities of nematodes than dessert bananas. In pots, P. goodeyi populations from Embu (1300 m a.s.l.) appeared more aggressive and with higher levels of multiplication than the population from Oyugis (1100 m a.s.l.). Cooking banana (‘Ng’ombe’) was more susceptible than dessert banana (‘Sukari Ndizi’). Nematode damage is more prominent in areas at higher altitude and on cooking banana cultivars. The findings provide key information in guiding informed and suitable management decision thresholds in relation to potential climate change.

Significant progressive heterobeltiosis in banana crossbreeding

Background Heterobeltiosis is the phenomenon when the hybrid’s performance is superior to its best performing parent. Banana (Musa spp. AAA) breeding is a tedious, time-consuming process, taking up to two decades to develop a consumer acceptable hybrid. Exploiting heterobeltiosis in banana breeding will help to select breeding material with high complementarity, thus increasing banana breeding efficiency. The aim of this study was therefore to determine and document the level of heterobeltiosis of bunch weight and plant stature in the East African highland bananas, in order to identify potential parents that can be used to produce offspring with desired bunch weight and stature after a few crosses. Results This research found significant progressive heterobeltiosis in cross-bred ‘Matooke’ (highland cooking) banana hybrids, also known as NARITAs, when grown together across years with their parents and grandparents in Uganda. Most (all except 4) NARITAs exhibited positive heterobeltiosis for bunch weight, whereas slightly more than half of them had negative heterobeltiosis for stature. The secondary triploid NARITA 17 had the highest heterobeltiosis for bunch weight: 249% versus its ‘Matooke’ grandparent and 136% against its primary tetraploid parent. Broad sense heritability (across three cropping cycles) for yield potential and bunch weight were high (0.84 and 0.76 respectively), while that of plant stature was very low (0.0035). There was a positive significant correlation (P < 0.05) between grandparent heterobeltiosis for bunch weight and genetic distance between parents (r = 0.39, P = 0.036), bunch weight (r = 0.7, P < 0.001), plant stature (r = 0.38, P = 0.033) and yield potential (r = 0.59, P < 0.001). Grandparent heterobeltiosis for plant stature was significantly, but negatively, correlated to the genetic distance between parents (r = − 0.6, P < 0.001). Conclusions Such significant heterobeltiosis exhibited for bunch weight is to our knowledge the largest among main food crops. Since bananas are vegetatively propagated, the effect of heterobeltiosis is easily fixed in the hybrids and will not be lost over time after the release and further commercialization of these hybrids.

Significant progressive heterobeltiosis in banana crossbreeding

Background: Heterobeltiosis is the phenomenon when the hybrid’s performance is superior to its best performing parent. Banana ( Musa spp. AAA) breeding is a tedious, time-consuming process, taking up to two decades to develop a consumer acceptable hybrid. Exploiting heterobeltiosis in banana breeding will help to select breeding material with high complementarity, thus increasing banana breeding efficiency. The aim of this study was therefore to determine and document the level of heterobeltiosis of bunch weight and plant stature in the East African highland bananas, in order to identify potential parents that can be used to produce offspring with desired bunch weight and stature after a few crosses.Results: This research found significant progressive heterobeltiosis in cross-bred ‘Matooke’ (highland cooking) banana hybrids, also known as NARITAs, when grown together across years with their parents and grandparents in Uganda. Most (all except 4) NARITAs exhibited positive heterobeltiosis for bunch weight, whereas slightly more than half of them had negative heterobeltiosis for stature. The secondary triploid NARITA 17 had the highest heterobeltiosis for bunch weight: 249% versus its matooke grandparent and 136% against its primary tetraploid parent. Broad sense heritability (across three cropping cycles) for yield potential and bunch weight were high (0.84 and 0.76 respectively), while that of plant stature was very low (0.0035). There was a positive significant correlation ( P < 0.05) between grandparent heterobeltiosis for bunch weight and genetic distance between parents (r = 0.39, P = 0.036), bunch weight (r = 0.7, P < 0.001), plant stature (r = 0.38, P = 0.033) and yield potential (r = 0.59, P < 0.001). Grandparent heterobeltiosis for plant stature was significantly, but negatively, correlated to the genetic distance between parents (r = -0.6, P < 0.001).Conclusions: Such significant heterobeltiosis exhibited for bunch weight is to our knowledge the largest among main food crops. Since bananas are vegetatively propagated, the effect of heterobeltiosis is easily fixed in the hybrids and will not be lost over time after the release and further commercialization of these hybrids.

Biscuit Making Potentials of Cooking Banana and Yellow Maize Flour Blends

The study was carried out to determine the biscuit making potentials of cooking banana and yellow maize flour blends. Cooking banana and yellow maize were processed and milled into flour then blended for composite biscuit production. The samples were coded as follows; A=100:0, B=90:10, C= 80:20, D=70:30, E=60:40 and F=0:100 of maize and cooking banana respectively. All the samples were subjected to laboratory analysis for proximate and minerals using standard methods. Sensory properties of the biscuit were also evaluated by 20 panelist. Data was subjected to analysis of variance (ANOVA) using SPSS and the result recorded as mean ± standard deviation while the mean was separated using Duncan New Multiple Range (P<0.05). The results were 0.50 to 120.75% protein, 4.08 to 5.10% moisture, 3.45 to 7.15% fat, 2.13 to 3.68% fibre and 77.81 to 82.91% carbohydrate. The minerals were 0.50 to 120.75 mg Ca, 4.10 to 12.75 mg Fe, 124.66 to 176.10 mg Mg, 10.32 to 24.75 mg Na, 1.45 to 2.13 mg Zn and 50. 22 to 116.33 mg P. There was significant different (P≤0.05) in texture, colour, appearance, flavor and overall acceptability of biscuits made from the composite flour. The study has revealed that biscuits of high nutrient dense and acceptable organoleptic properties could be produced from yellow maize and cooking banana composite flour blends. The use of yellow maize and cooking banana flour in biscuits preparation resulted in significant improvement in the nutrient content of the composite biscuits.